BIOS Interupt service
-----------------------------------------------------------
INT 00 - DIVIDE ERROR (internal interrupt)
Automatically called at end of DIV or IDIV operation that results in error.
Normally set by DOS to display an error message and abort the program.
-----------------------------------------------------------
INT 01 - SINGLE-STEP (internal interrupt)
Generated at end of each machine instruction if TF bit in FLAGS is set.
This is what makes the T command of DEBUG work for single-stepping. It is
not generated after MOV to segment register or POP of segment register
(unless you have a very early 8088 with a microcode bug).
-----------------------------------------------------------
INT 02 - NMI (NON-MASKABLE INTERRUPT)
Generated by NMI signal in hardware. This signal has various uses:
Parity error: all except Jr and CONV
Coprocessor interrupt: all except Jr and CONV
Keyboard interrupt: Jr, CONV
I/O channel check: CONV, PS50+
Disk-controller power-on request: CONV
System suspend: CONV
Real-time clock: CONV
System watch-dog timer, time-out interrupt: PS50+
DMA timer time-out interrupt: PS50+
-----------------------------------------------------------
INT 03 - 1-BYTE INTERRUPT (internal interrupt)
Generated by opcode CCh. Similar to 8080's RST instruction. Generally
used to set breakpoints for DEBUG.
Also used by Turbo Pascal versions 1,2,3 when {$U+} specified
-----------------------------------------------------------
INT 04 - OVERFLOW (internal interrupt)
Generated by INTO instruction if OF flag is set. If flag is not set, INTO
is effectively a NOP. Used to trap any arithmetic errors when program is
ready to handle them rather than immediately when they occur.
-----------------------------------------------------------
INT 05 - PRINT-SCREEN KEY
Automatically called by keyboard scan when print-screen key is pressed.
Normally executes routine to print the screen, but may call any routine that
can safely be executed from inside the keyboard scanner. Status and result
byte for default handler is at address 0050:0000.
-----------------------------------------------------------
INT 05 - BOUND CHECK FAILED (80186/80286 internal interrupt)
Generated by BOUND instruction when the value to be tested is less than the
indicated lower bound or greater than the indicated upper bound.
-----------------------------------------------------------
INT 06 - UNDEFINED OPCODE (80286 internal interrupt)
-----------------------------------------------------------
INT 07 - NO MATH UNIT AVAILABLE (80286 protected-mode internal)
-----------------------------------------------------------
INT 08 thru 0F - VECTORED HARDWARE LINES
In IBM, these 8 interrupts are generated in response to IRQ 0 through
IRQ 7 (if enabled via port 21h).
[Tandy 1000] [Adapters]
IRQ0 - timer interrupt
IRQ1 - keyboard interrupt
IRQ2 - EGA vertical retrace [fixed disk] [TOPS&PCnet default]
IRQ3 - serial port 2 (com2:) [TOPS&PCnet alternate]
IRQ4 - serial port 1 (com1:)
IRQ5 - fixed disk (PC/AT: LPT2) [60 Hz ram refresh]
IRQ6 - diskette interrupt
IRQ7 - PPI interrupt (lpt1:, lpt2:)
-----------------------------------------------------------
INT 08 - DOUBLE FAULT (80286 protected-mode internal)
Called when multiple exceptions occur on one instruction, or an exception
occurs in an exception handler. If an exception occurs in the double fault
handler, the CPU goes into SHUTDOWN mode (which circuitry in the PC/AT
converts to a reset).
-----------------------------------------------------------
INT 09 - MATH UNIT PROTECTION FAULT (80286 protected-mode internal)
-----------------------------------------------------------
INT 0A - INVALID TASK STATE SEGMENT (80286 protected-mode internal)
-----------------------------------------------------------
INT 0B - NOT PRESENT (80286 protected-mode internal)
Generated when loading a segment register if the segment descriptor
indicates that the segment is not currently in memory.
-----------------------------------------------------------
INT 0C - STACK FAULT (80286 protected-mode internal)
Generated on stack overflow/underflow. Note that the 80286 will shut down
in real mode if SP=1 before a push.
-----------------------------------------------------------
INT 0D - GENERAL PROTECTION VIOLATION (80286 internal interrupt)
Called in real mode when an instruction attempts to access a word operand
located at offset FFFFh
-----------------------------------------------------------
INT 0E - PAGE FAULT (80386 native-mode internal interrupt)
-----------------------------------------------------------
INT 10 - VIDEO - SET VIDEO MODE
AH = 00h
AL = mode (graphics mode if graphics resolution listed)
text pixel graphic color disp scrn system
resol box resoltn page addr
00h = 40x25 8x8 B&W 8 B800 CGA
01h = 40x25 8x8 16 8 B800 CGA
02h = 80x25 8x8 B&W 4 B800 CGA
03h = 80x25 8x8 16 4 B800 CGA
04h = 40x25 8x8 320x200 4 1 B800 CGA
05h = 40x25 8x8 320x200 4 gray 1 B800 CGA
06h = 80x25 8x8 640x200 B&W 1 B800 CGA
07h = 80x25 8x14 mono 1 B000 MDA/Hercules
08h = 160x200 16 ??? B800 PCjr/Tandy 1000
09h = 320x200 16 ??? B800 PCjr/Tandy 1000
0Ah = 640x200 4 ??? B800 PCjr/Tandy 1000
0Bh = reserved (used internally by EGA BIOS)
0Ch = reserved (used internally by EGA BIOS)
0Dh = 320x200 16 ??? A000 EGA/VGA
0Eh = 640x200 16 ??? A000 EGA/VGA
0Fh = 640x350 mono ??? A000 EGA/VGA
10h = 640x350 4or16 ??? A000 EGA/VGA
11h = 640x480 mono ??? A000 VGA/MCGA
12h = 640x480 16 ??? A000 VGA
13h = 320x200 256 ??? A000 VGA/MCGA
18h = 132x44 8x8 mono Tseng Labs EVA
19h = 132x25 8x14 mono Tseng Labs EVA
1Ah = 132x28 8x13 mono Tseng Labs EVA
22h = 132x44 8x8 ??? Tseng, Ahead
23h = 132x25 6x14 ??? Tseng Labs EVA
= 132x25 8x14 ??? Ahead Systems EGA2001
24h = 132x28 6x13 ??? Tseng Labs EVA
25h = 80x60 8x8 640x480 ??? Tseng Labs EVA
26h = 80x60 8x8 ??? Tseng Labs EVA
= 80x60 8x8 640x480 ??? Ahead Systems EGA2001
30h = ???x??? ??? AT&T 6300
40h = 640x400 2 B800 AT&T 6300
48h = 80x50 640x400 2 B800 AT&T 6300
50h = 132x25 9x14 mono Ahead Systems EGA2001
= 80x30 8x16 640x480 ??? Paradise EGA-480
51h = 80x30 8x16 ??? Paradise EGA-480
52h = 132x44 9x8 mono Ahead Systems EGA2001
54h = 132x43 8x8 ??? Paradise EGA-480
55h = 132x25 8x14 ??? Paradise EGA-480
56h = 132x43 8x8 3??? 2 B000 NSI Smart EGA+
57h = 132x25 8x14 3??? 4 B000 NSI Smart EGA+
60h = 80x??? ???x400 ??? Corona/Cordata BIOS v4.10+
61h = ???x400 ??? Corona/Cordata BIOS v4.10+
71h = 100x35 8x16 800x600 16of64 A000 NSI Smart EGA+
74h = 640x400 ??? Toshiba 3100
D0h = 640x400 2 DEC VAXmate AT&T mode
??? = 640x225 ??? Z-100
??? = 640x400 ??? Z-100
-----------------------------------------------------------
INT 10 - VIDEO - SET CURSOR CHARACTERISTICS
AH = 01h
CH bits 0-4 = start line for cursor in character cell
bits 5-6 = blink attribute
(00=normal, 01=invisible, 10=slow, 11=fast)
CL bits 0-4 = end line for cursor in char. cell
-----------------------------------------------------------
INT 10 - VIDEO - SET CURSOR POSITION
AH = 02h
DH,DL = row, column (0,0 = upper left)
BH = page number
0 in graphics modes
0-3 in modes 2&3
0-7 in modes 0&1
-----------------------------------------------------------
INT 10 - VIDEO - READ CURSOR POSITION
AH = 03h
BH = page number
0 in graphics modes
0-3 in modes 2&3
0-7 in modes 0&1
Return: DH,DL = row,column
CH = cursor start line
CL = cursor end line
-----------------------------------------------------------
INT 10 - VIDEO - READ LIGHT PEN POSITION (all but PS)
AH = 04h
Return: AH = 0: light pen switch not activated
AH = 1: light pen values in registers
DH,DL = row,column of current position
CH = raster line (0-199) (EGA) old graphics modes
CX = (EGA) raster line (0-nnn) new graphics modes
BX = pixel column (0-319 or 0-639)
-----------------------------------------------------------
INT 10 - VIDEO - SELECT DISPLAY PAGE
AH = 05h
AL =
0-7: new page value for modes 0 & 1
0-3: new page value for modes 2 & 3
80h: read CRT/CPU page registers [PCjr only]
81h: set CPU page register to value in BL [PCjr only]
82h: set CRT page register to value in BH [PCjr only]
83h: set both display registers [PCjr only]
{Corona/Cordata BIOS v4.10+}
0: set address of graphics bitmap buffer (video modes 60h,61h)
BX = segment of buffer
0Fh: get address of graphics bitmap buffer (video modes 60h,61h)
Return: BH = CRT page register (if AL >= 80h)
BL = CPU page register (if AL >= 80h)
DX = segment of graphics bitmap buffer (video modes 60h,61h; AL=0Fh)
-----------------------------------------------------------
INT 10 - VIDEO - SCROLL PAGE UP
AH = 06h
AL = number of lines to scroll window (0 = blank whole window)
BH = attributes to be used on blanked lines
CH,CL = row,column of upper left corner of window to scroll
DH,DL = row,column of lower right corner of window
-----------------------------------------------------------
INT 10 - VIDEO - SCROLL PAGE DOWN
AH = 07h
AL = number of lines to scroll window (0 = blank whole window)
BH = attributes to be used on blanked lines
CH,CL = row,column of upper left corner of window to scroll
DH,DL = row,column of lower right corner of window
-----------------------------------------------------------
INT 10 - VIDEO - READ ATTRIBUTES/CHARACTER AT CURSOR POSITION
AH = 08h
BH = display page
Return: AL = character
AH = attribute of character (alpha modes)
-----------------------------------------------------------
INT 10 - VIDEO - WRITE ATTRIBUTES/CHARACTERS AT CURSOR POS
AH = 09h
AL = character
BH = display page - alpha modes
BL = attributes of char (alpha modes) or color (graphics modes)
if bit 7 == 1 in graphics mode, character is xor'ed onto screen
CX = number of times to write character
-----------------------------------------------------------
INT 10 - VIDEO - WRITE CHARACTERS ONLY AT CURSOR POS
AH = 0Ah
AL = character
BH = display page - alpha mode
BL = color of character (graphics mode)
CX = number of times to write character
(EGA) in graphics modes, replication count in CX works correctly
only if all character written are contains on the same row
-----------------------------------------------------------
INT 10 - VIDEO - SET COLOR PALETTE
AH = 0Bh
BH = 0
BL = border color (0-15) (text modes)
border color and background color (graphics modes)
(EGA)
BL = border color (0-15) and high-intensity background color
(16-31??? maybe should be high nybble?)
BH = 1
BL = palette (0/1)
-----------------------------------------------------------
INT 10 - VIDEO - WRITE DOT ON SCREEN
AH = 0Ch
AL = color of dot (0/1 in mode 6, 0-3 in modes 4 and 5)
if bit 7 set, new color will be XORed with current pixel
DX = row (0 - 199)
CX = column (0 - 319 in modes 4/5/13, 0 - 639 in modes 6/14/15/16)
Note: only valid in graphics modes
-----------------------------------------------------------
INT 10 - VIDEO - READ DOT ON SCREEN
AH = 0Dh
CX = column (0 - 319 or 639)
DX = row (0 - 199)
Return: AL = color read
-----------------------------------------------------------
INT 10 - VIDEO - WRITE CHARACTER AND ADVANCE CURSOR (TTY WRITE)
AH = 0Eh
AL = character
BH = display page (alpha modes)
BL = foreground color (graphics modes)
-----------------------------------------------------------
INT 10 - VIDEO - GET CURRENT VIDEO MODE
AH = 0Fh
Return: AH = number of columns on screen
AL = current video mode (see INT 10h/AH=00h)
BH = current active display page
-----------------------------------------------------------
INT 10 - VIDEO - SET PALETTE REGISTERS (Jr, PS, TANDY 1000, EGA, VGA)
AH = 10h
AL = 0: set palette register
BL = palette register to set
BH = color value to store
AL = 1: set border color register
BH = color value to store
AL = 2: set all palette registers and overscan
ES:DX = pointer to 17-byte list
bytes 0-15 = values for palette regs. 0-15
byte 16 = value for border register
(EGA/VGA/MCGA)
AL = 3: toggle intensity/blinking bit
BL = 0: enable intensity
BL = 1: enable blink
(VGA/MCGA)
AL = 07h: read individual palette register (VGA only)
BL = palette register number
Return: BH = palette register value
AL = 08h: read overscan (border color) register (VGA only)
Return: BH = value
AL = 09h: read all palette registers and overscan register (VGA only)
ES:DX = buffer address (17 bytes)
AL = 10h: set individual DAC register
BX = register number
CH = new value for green (0-63)
CL = new value for blue (0-63)
DH = new value for red (0-63)
AL = 12h: set block of DAC registers
BX = starting color register
CX = number of registers to set
ES:DX = Table of 3*CX bytes where each 3 byte
group represents one byte each of red, green and blue (0-63)
AL = 13h: select video DAC color page (VGA only)
BL = 00h Select paging mode
BH = 00h Select 4 blocks of 64
BH = 01h Select 16 blocks of 16
BL = 01h Select Page
BH = page number (00h to 03h) or (00h to 0Fh)
AL = 15h: read individual DAC register
BL = palette register number
Return: DH = red value
CH = green value
CL = blue value
AL = 17h: read block of DAC registers
BX = starting palette register
CX = number of palette registers to read
ES:DX = buffer (3 * CX bytes in size)
Return: CX number of red, green and blue triples
in buffer
AL = 18h *UNDOCUMENTED* set PEL mask
BL = new PEL value
AL = 19h *UNDOCUMENTED* read PEL mask
BL = value read
AL = 1Ah: read video DAC color-page state (VGA only)
Return: BL = paging mode
BH = current page
AL = 1Bh: perform gray-scale summing
BX = starting palette register
CX = number of registers to convert
-----------------------------------------------------------
INT 10 - VIDEO - CHARACTER GENERATOR FUNCTIONS (PS, EGA, VGA)
AH = 11h
The following functions will cause a mode set, completely resetting
the video environment, but without clearing the video buffer
AL = 00h, 10h: load user-specified patterns
ES:BP = pointer to user table
CX = count of patterns to store
DX = character offset into map 2 block
BL = block to load in map 2
BH = number of bytes per character pattern
AL = 01h, 11h: load ROM monochrome patterns (8 by 14)
BL = block to load
AL = 02h, 12h: load ROM 8 by 8 double-dot patterns
BL = block to load
AL = 03h: set block specifier
BL = block specifier
AL = 04h, 14h: load ROM 8x16 character set (VGA)
The routines called with AL=1xh are designed to be called only
immediately after a mode set and are similar to the routines called
with AL=0xh, except that:
Page 0 must be active.
Bytes/character is recalculated.
Max character rows is recalculated.
CRT buffer length is recalculated.
CRTC registers are reprogrammed as follows:
R09 = bytes/char-1 ; max scan line (mode 7 only)
R0A = bytes/char-2 ; cursor start
R0B = 0 ; cursor end
R12 = ((rows+1)*(bytes/char))-1 ; vertical display end
R14 = bytes/char ; underline loc
(*** BUG: should be 1 less ***)
The following functions are meant to be called only after a mode set:
AL = 20h: user 8 by 8 graphics characters (INT 1Fh)
ES:BP = pointer to user table
AL = 21h: user graphics characters
ES:BP = pointer to user table
CX = bytes per character
BL = row specifier
0: user set
DL = number of rows
1: 14 rows
2: 25 rows
3: 43 rows
AL = 22h: ROM 8 by 14 set
BL = row specifier
AL = 23h: ROM 8 by 8 double dot
BL = row specifier
AL = 24h: load 8x16 graphics characters (VGA)
AL = 30h: return information
BH = pointer specifier
0: INT 1Fh pointer
1: INT 44h pointer
2: ROM 8 by 14 character font pointer
3: ROM 8 by 8 double dot font pointer
4: ROM 8 by 8 DD font (top half)
5: ROM alpha alternate (9 by 14) pointer
Returns: ES:BP = specified pointer value
CX = bytes/character
DL = character rows on screen
-----------------------------------------------------------
INT 10 - VIDEO - ALTERNATE FUNCTION SELECT (PS, EGA, VGA, MCGA)
AH = 12h
BL = 10h: return EGA information
Returns:
BH = 0: color mode in effect (3Dx)
1: mono mode in effect (3Bx)
BL = 0: 64k bytes memory installed
1: 128k bytes memory installed
2: 192k bytes memory installed
3: 256k bytes memory installed
CH = feature bits
CL = switch settings
BL = 20h: select alternate print screen routine
BL = 30h: select vertical resolution for alphanumeric modes (VGA only)
AL = 00h 200 scan lines
01h 350 scan lines
02h 400 scan lines
Return: AL = 12h if function supported
BL = 31h: enable/disable default palette loading (VGA/MCGA)
AL = 00h enable default palette loading
01h disable default palette loading
Return: AL = 12h if function was supported
BL = 32h: enable/disable video addressing (VGA/MCGA)
AL = 00h enable video
01h disable video
Return: AL = 12h if function was supported
BL = 33h: enable/disable default gray-scale summing (VGA/MCGA)
AL = 00h enable gray scale summing
01h disable gray scale summing
Return: AL = 12h if function was supported
BL = 34h: enable/disable alphanumeric cursor emulation (VGA only)
AL = 00h enable cursor emulation
01h disable cursor emulation
Return: AL = 12h if function was supported
BL = 35h: PS/2 display-switch interface
AL = 00h initial adapter video off
01h initial planar video on
02h switch active video off
03h switch inactive video on
80h *UNDOCUMENTED* set system board video active flag
ES:DX = buffer (128 byte save area if AL = 0, 2 or 3)
BL = 36h: video refresh control (VGA/PS)
AL = 0 enable refresh
1 disable refresh
Return: AL = 12h if function supported
-----------------------------------------------------------
INT 10 - VIDEO - WRITE STRING (AT,XT286,PS,EGA,VGA)
AH = 13h
AL = mode
bit 0: set in order to move cursor after write
bit 1: set if string contains alternating characters and attributes
BL = attribute if AL bit 1 clear
BH = display page number
DH,DL = row,column of starting cursor position
CX = length of string
ES:BP = pointer to start of string
-----------------------------------------------------------
INT 10 - VIDEO - LOAD LCD CHARACTER FONT (CONVERTIBLE)
AH = 14h
AL = 0 load user-specified font
ES:DI = pointer to character font
BH = number of bytes per character
BL = 0: load main font (block 0)
1: load alternate font (block 1)
CX = number of characters to store
DX = character offset into RAM font area
AL = 1 load system rom default font
BL = 0: load main font (block 0)
1: load alternate font (block 1)
AL = 2 set mapping of LCD high intensity attributes
BL = 0: ignore high intensity attribute
1: map high intensity to underscore
2: map high intensity to revrese video
3: map high intensity to selected alternate font
-----------------------------------------------------------
INT 10 - VIDEO - GET PHYSICAL DISPLAY PARAMETERS (CONVERTIBLE)
AH = 15h
Return: AX = alternate display adapter type
ES:DI = pointer to parameter table
word 0: monitor model number
1: vertical pixels per meter
2: horizontal pixels per meter
3: total vertical pixels
4: total horizontal pixels
5: horizontal pixel separation in micrometers
6: vertical pixel separation in micrometers
-----------------------------------------------------------
INT 10 - VIDEO - DISPLAY COMBINATION (PS,VGA/MCGA)
AH = 1Ah
AL = 0: read display combination code
Return: BL = active display code
BH = alternate display code
1: set display combination code
BL = active display code
BH = alternate display code
Return: AL = 1Ah if function was supported
Display combination codes:
00h no display
01h monochrome adapter w/ monochrome display
02h CGA w/ color display
03h reserved
04h EGA w/ color display
05h EGA w/ monochrome display
06h PGA w/ color display
07h VGA w/ monochrome analog display
08h VGA w/ color analog display
09h reserved
0Ah reserved
0Bh MCGA w/ monochrome analog display
0Ch MCGA w/ color analog display
FFh unknown display type
-----------------------------------------------------------
INT 10 - VIDEO - FUNCTIONALITY/STATE INFORMATION (PS,VGA/MCGA)
AH = 1Bh
BX = implementation type
BX = 0000h return funtionality/state information
ES:DI buffer (64 bytes)
DI+00 static funtionality table
DI+04 video mode in effect
DI+05 number of columns
DI+07 length of regen buffer in bytes
DI+09 starting address og regen buffer
DI+0B cursor position for page 0
DI+0D cursor position for page 1
DI+0F cursor position for page 2
DI+11 cursor position for page 3
DI+13 cursor position for page 4
DI+15 cursor position for page 5
DI+17 cursor position for page 6
DI+19 cursor position for page 7
DI+1B cursor type
DI+1D active display page
DI+1E CRTC port address
DI+20 current setting of register (3?8)
DI+21 current setting of register (3?9)
DI+22 number of rows
DI+23 bytes/character
DI+25 DCC of active display
DI+26 DCC of alternate display
DI+27 number of colors supported in current mode
DI+29 number of pages supported in current mode
DI+2A number of scan lines active
(0,1,2,3) = (200,350,400,480)
DI+2B primary character block
DI+2C secondary character block
DI+2D Miscellaneous flags
bit 0 all modes on all displayss on
1 gray summing on
2 monochrome display attached
3 default palette loading disabled
4 cursor emulation enabled
5 0 = intensity; 1 = blinking
6 reserved
7 reserved
DI+2E to DI+30 reserved
DI+32 save pointer state flags
bit 0 512 character set active
1 dynamic save area present
2 alpha font override active
3 graphics font override active
4 palette override active
5 DCC override active
6 reserved
7 reserved
DI+33 to DI+3F reserved
State Functionality Table format (16 bytes)
address+00 modes supported #1
bit 0 to bit 7 = 1 modes 0,1,2,3,4,5,6 supported
+01 modes supported #2
bit 0 to bit 7 = 1 modes 8,9,A,B,C,D,E,F supported
+02 modes supported #3
bit 0 to bit 3 = 1 modes 10,11,12,13 supported
bit 4 to bit 7 reserved
+03 to +06 reserved
+07 scan lines supported
bit 0 to bit 2 = 1 scan lines 200,350,400 supported
+08 maximum number of active character blocks in text modes
+09 total blocks available in text modes
+0A miscellaneous function flags #1
bit 0 all modes on all displays function supported
1 gray summing function supported
2 character font loading function supported
3 default palette loading enable/disable supported
4 cursor emulation function supported
5 EGA palette present
6 color palette present
7 color paging function supported
+0B miscellaneous function flags #2
bit 0 light pen supported
1 save/restore state function 1C supported
2 intensity blinking function supported
3 Display Combination Code supported
4 reserved
5 reserved
6 reserved
7 reserved
+0C to +0D reserved
+0E Save pointer function flags
bit 0 512 character set supported
1 dynamic save area supported
2 alpha font override supported
3 graphics font override supported
4 palette override supported
5 DCC extension supported
6 reserved
7 reserved
+07 reserved
-----------------------------------------------------------
INT 10 - VIDEO - SAVE/RESTORE VIDEO STATE (PS50+,VGA)
AH = 1Ch
CX = requested states
bit 0 video hardware
1 BIOS data areas
2 color registers and state
3 reserved
4 reserved
5 reserved
6 reserved
7 reserved
AL = 0: return state buffer size in 64 byte blocks
1: save video state
ES:BX = buffer address
2: restore video state
ES:BX = buffer address of previously saved state
Return: AL = 1Ch if function supported
-----------------------------------------------------------
INT 10 - VIDEO - SET GRAPHICS MODE (Hercules GRAFIX)
AH = 40h
-----------------------------------------------------------
INT 10 - VIDEO - SET TEXT MODE (Hercules GRAFIX)
AH = 41h
-----------------------------------------------------------
INT 10 - VIDEO - CLEAR CURRENT PAGE (Hercules GRAFIX)
AH = 42h
-----------------------------------------------------------
INT 10 - VIDEO - SELECT DRAWING PAGE (Hercules GRAFIX)
AH = 43h
AL = Page number (0,1)
-----------------------------------------------------------
INT 10 - VIDEO - SELECT DRAWING FUNCTION (Hercules GRAFIX)
AH = 44h
AL = 0 : Clear pixels
AL = 1 : Set pixels
AL = 2 : Invert pixels
-----------------------------------------------------------
INT 10 - VIDEO - SELECT PAGE TO DISPLAY (Hercules GRAFIX)
AH = 45h
AL = Page number (0,1)
-----------------------------------------------------------
INT 10 - VIDEO - DRAW ONE PIXEL (Hercules GRAFIX)
AH = 46h
DI = x (0-720)
BP = y (0-347)
Note: Function 44h determines operation and function 43h
page to use.
-----------------------------------------------------------
INT 10 - VIDEO - FIND PIXEL VALUE (Hercules GRAFIX)
AH = 47h
DI = x (0-720)
BP = y (0-347)
Return: AL = 0 Pixel clear
AL = 1 Pixel set
Note: Function 43h specifies page that is used.
-----------------------------------------------------------
INT 10 - VIDEO - MOVE TO POINT (Hercules GRAFIX)
AH = 48h
DI = x (0-720)
BP = y (0-347)
-----------------------------------------------------------
INT 10 - VIDEO - DRAW TO POINT (Hercules GRAFIX)
AH = 49h
DI = x (0-720)
BP = y (0-347)
Note: Function 48h or 49h specify first point, 44h operation
and 43h page to use.
-----------------------------------------------------------
INT 10 - VIDEO - BLOCK FILL (Hercules GRAFIX)
AH = 4Ah
-----------------------------------------------------------
INT 10 - VIDEO - DISPLAY CHARACTER (Hercules GRAFIX)
AH = 4Bh
AL = Character to display
DI = x (0-720)
BP = y (0-347)
Note: Unlike the other BIOS character functions character
position is specified in pixels rather than rows and
columns.
-----------------------------------------------------------
INT 10 - VIDEO - DRAW ARC (Hercules GRAFIX)
AH = 4Ch
-----------------------------------------------------------
INT 10 - VIDEO - DRAW CIRCLE (Hercules GRAFIX)
AH = 4Dh
-----------------------------------------------------------
INT 10 - VIDEO - FILL AREA (Hercules GRAFIX)
AH = 4Eh
-----------------------------------------------------------
INT 10 - Direct Graphics Interface Standard (DGIS) - INQUIRE AVAILABLE DEVICES
AX = 6A00h
BX = 0
CX = 0
DX = buffer length (may be 0)
ES:DI = address of buffer
Return: BX = number of bytes stored in buffer
CX = bytes required for all descriptions (0 if no DGIS)
Note: buffer contains descriptions and addresses of DGIS-compatible
display(s) and printer(s)
-----------------------------------------------------------
INT 10 - DGIS - REDIRECT CHARACTER OUTPUT
AX = 6A01h
CX = 0
ES:DI = address of device to send INT 10 output to
Return: CX = 0 output could not be redirected
else INT 10h output now routed to requested display
-----------------------------------------------------------
INT 10 - DGIS - INQUIRE INT 10 OUTPUT DEVICE
AX = 6A02h
ES:DI = 0:0
Return: ES:DI = 0:0 if current display is non-DGIS
else address of the current DGIS INT 10 display
-----------------------------------------------------------
INT 10 - VIDEO - GET VIDEO RAM ADDRESS (TANDY 1000)
AH = 70h
Return: AX = segment address of the following
[BX] = offset address of green plane
[CX] = segment address of green plane
[DX] = segment address of red/blue plane
(red offset = 0, blue offset = 4000)
-----------------------------------------------------------
INT 10 - VIDEO - GET INCRAM ADDRESSES (TANDY 1000)
AH = 71h
Return: AX = segment address of the following
[BX] = segment address of INCRAM
[CX] = offset address of INCRAM
-----------------------------------------------------------
INT 10 - VIDEO - SCROLL SCREEN RIGHT (TANDY 1000)
AH = 72h
AL = number of columns blanked at left of window
0 = blank entire window
BH = attributes to be used on blank columns
CH,CL = row, column of upper left corner of window
DH,DL = row, column of lower right corner
----------------------------------------------------------
INT 10 - VIDEO - SCROLL SCREEN LEFT (TANDY 1000)
AH = 73h
AL = number of columns blanked at right of window
0 = blank entire window
BH = attributes to be used on blank columns
CH,CL = row, column of upper left corner of window
DH,DL = row, column of lower right corner
-----------------------------------------------------------
INT 10 - VIDEO (DESQview) - ???
AH = 80h
DX = 4456h ('DV')
ES:DI = pointer to ???
Return: DS = segment of DESQview data structure for video buffer
Note: this function is probably meant for internal use only, due to the magic
value required in DX
-----------------------------------------------------------
INT 10 - VIDEO (DESQview) - ???
AH = 81h
DX = 4456h
Return: ES = segment of DESQview data structure for video buffer
BYTE ES:[0] = current window number
Note: this function is probably meant for internal use only, due to the magic
value required in DX
-----------------------------------------------------------
INT 10 - VIDEO (DESQview) - ???
AH = 82h
DX = 4456h
Return: DS = segment in DESQview for ???
ES = segment of DESQview data structure for video buffer
AL = current window number
AH = ???
BL = direct screen writes
0 program does not do direct writes
1 program does direct writes, so shadow buffer not usable
BH = ???
CL = ???
CH = ???
Note: this function is probably meant for internal use only, due to the magic
value required in DX
-----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - READ ONE REGISTER
AH = F0h
BH = 00h
BL = pointer for pointer/data chips
Pointer/data chips
00h CRTC (3B4h mono modes, 3D4h color modes)
08h Sequencer 3C4h
10h Graphics Controller 3CEh
18h Attribute Controller 3C0h
Single registers
20h Miscellaneous Output register 3C2h
28h Feature Control register (3BAh mono modes, 3DAh color modes)
30h Graphics 1 Position register 3CCh
38h Graphics 2 Position register 3CAh
DX = port number
Return: BL = data
-----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - WRITE ONE REGISTER
AH = F1h
BH = 00h
BL = pointer for pointer/data chips
Pointer/data chips
00h CRTC (3B4h mono modes, 3D4h color modes)
08h Sequencer 3C4h
10h Graphics Controller 3CEh
18h Attribute Controller 3C0h
Single registers
20h Miscellaneous Output register 3C2h
28h Feature Control register (3BAh mono modes, 3DAh color modes)
30h Graphics 1 Position register 3CCh
38h Graphics 2 Position register 3CAh
DX = port number
Return: BL = data
-----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - READ REGISTER RANGE
AH = F2h
CH = starting pointer value
CL = Number of registers (>1)
DX = port number
00h CRTC (3B4h mono modes, 3D4h color modes)
08h Sequencer 3C4h
10h Graphics Controller 3CEh
18h Attribute Controller 3C0h
ES:BX buffer size of CL
-----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - WRITE REGISTER RANGE
AH = F3h
CH = starting pointer value
CL = Number of registers (>1)
DX = port number
00h CRTC (3B4h mono modes, 3D4h color modes)
08h Sequencer 3C4h
10h Graphics Controller 3CEh
18h Attribute Controller 3C0h
ES:BX buffer size of CL
-----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - READ REGISTER SET
AH = F4h
CX = number of registers (>1)
ES:BX address of table of records in this format:
bytes 1-2 port number
Pointer/data chips
00h CRTC (3B4h mono modes, 3D4h color modes)
08h Sequencer 3C4h
10h Graphics Controller 3CEh
18h Attribute Controller 3C0h
Single registers
20h Miscellaneous Output register 3C2h
28h Feature Control register (3BAh mono modes, 3DAh color)
30h Graphics 1 Position register 3CCh
38h Graphics 2 Position register 3CAh
byte 3 pointer value (0 for single registers)
byte 4 EGA Register Interface returns data here
-----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - READ REGISTER SET
AH = F5h
CX = number of registers (>1)
ES:BX address of table of records in this format:
bytes 1-2 port number
Pointer/data chips
00h CRTC (3B4h mono modes, 3D4h color modes)
08h Sequencer 3C4h
10h Graphics Controller 3CEh
18h Attribute Controller 3C0h
Single registers
20h Miscellaneous Output register 3C2h
28h Feature Control register (3BAh mono modes, 3DAh color)
30h Graphics 1 Position register 3CCh
38h Graphics 2 Position register 3CAh
byte 3 pointer value (0 for single registers)
byte 4 EGA Register Interface writes data here
----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - REVERT TO DEFAULT REGISTERS
AH = F6h
----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - DEFINE DEFAULT REGISTER TABLE
AH = F7h
DX = port number
Pointer/data chips
00h CRTC (3B4h mono modes, 3D4h color modes)
08h Sequencer 3C4h
10h Graphics Controller 3CEh
18h Attribute Controller 3C0h
Single registers
20h Miscellaneous Output register 3C2h
28h Feature Control register (3BAh mono modes, 3DAh color modes)
30h Graphics 1 Position register 3CCh
38h Graphics 2 Position register 3CAh
ES:BX address of table of one byte entries, one byte
to be written to each register
----------------------------------------------------------
INT 10 - Microsoft Mouse driver EGA support - INTERROGATE DRIVER
AH = FAh
BX = 0
Return: BX = 0 if mouse driver not present
ES:BX pointer to EGA Register Interface
version number, if present:
byte 1 = major release number
byte 2 = minor release number
----------------------------------------------------------
INT 10 - VIDEO (TopView) - GET VIDEO BUFFER
AH = FEh
ES:DI = segment:offset of assumed video buffer
Return: ES:DI = segment:offset of actual video buffer
-----------------------------------------------------------
INT 10 - VIDEO (TopView) - UPDATE REAL SCREEN FROM VIDEO BUFFER
AH = FFh
CX = number of sequential characters that have been modified
DI = offset of first character that has been modified
ES = segment of video buffer
Note: avoid CX=0
-----------------------------------------------------------
INT 11 - EQUIPMENT DETERMINATION
Return: AX = equipment flag bits
0 diskette installed
1 8087 present
2,3 always = 11
4,5 initial video mode
01 = 40x25 color
10 = 80x25 color
11 = 80X25 IBM monochrome
6,7 number of diskette drives (only if bit 0 = 1)
00 = 1, 01 = 2, 10 = 3, 11 = 4
8 0 = dma present, 1 = no dma on system (PCjr???)
9,10,11 number of RS232 cards
12 game I/O attached
13 serial printer installed (IBM-PCjr)
internal modem installed (Convertible)
14,15 number of printers
-----------------------------------------------------------
INT 12 - MEMORY SIZE
Return: AX = number of contiguous 1K blocks of memory
-----------------------------------------------------------
INT 13 - DISK - RESET DISK SYSTEM
AH = 00h
-----------------------------------------------------------
INT 13 - DISK - STATUS OF DISK SYSTEM
AH = 01h
Return: AL = status
00h = successful completion
01h = bad command
02h = address mark not found
03h = write attempted on write-protected disk
04h = sector not found
05h = reset failed (hard disk)
06h = diskette changed
07h = parameter act. failed (hard disk)
08h = DMA overrun
09h = DMA across 64K boundary
0Ah = bad sector detected (hard disk)
0Bh = bad track detected (hard disk)
0Ch = unsupported track
10h = bad CRC/ECC
11h = data ECC corrected
20h = controller failure
40h = seek failed
80h = time out
AAh = drive not ready (hard disk)
BBh = undefined error (hard disk)
-----------------------------------------------------------
INT 13 - DISK - READ SECTORS INTO MEMORY
AH = 02h
AL = number of sectors to read
CH = track (for hard disk, bits 8,9 in high bits of CL)
CL = sector
DH = head
DL = drive
ES:BX = address of buffer to fill
Return: CF = set if error occurred
AH = status (see AH=1 above)
AL = number of sectors read
-----------------------------------------------------------
INT 13 - DISK - WRITE SECTORS FROM MEMORY
AH = 03h
AL = number of sectors to write
CH = track (for hard disk, bits 8,9 in high bits of CL)
CL = sector
DH = head
DL = drive
ES:BX = address of buffer
Return: CF = set if error occurred
AH = status (see AH=1 above)
AL = number of sectors written
-----------------------------------------------------------
INT 13 - DISK - VERIFY SECTORS
AH = 04h
AL = number of sectors to verify
CH = track (for hard disk, bits 8,9 in high bits of CL)
CL = sector
DH = head
DL = drive
Return: CF = set if error occurred
AH = status (see AH=1 above)
AL = number of sectors verified
-----------------------------------------------------------
INT 13 - FLOPPY - FORMAT TRACK
AH = 05h
AL = number of sectors to create on this track
CH = track
CL = sector
DH = head
DL = drive
ES:BX = pointer to array of 4-byte address fields
byte 1 = track
byte 2 = head
byte 3 = sector
byte 4 = bytes/sector 0=128, 1=256, 2=512, 3=1024
Return: CF set if error occurred
AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - FIXED DISK - FORMAT TRACK
AH = 05h
AL = interleave value (XT only)
ES:BX = 512-byte format buffer
the first 2*(sectors/track) bytes contain F,N for each sector
F = 00 for good sector, 80h for bad sector
N = sector number
CH = cylinder number (bits 8,9 in high bits of CL)
CL = sector number
DH = head
DL = drive
Return: AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - FIXED DISK - FORMAT TRACK AND SET BAD SECTOR FLAGS (XT,PORT)
AH = 06h
AL = interleave value (XT only)
ES:BX = 512-byte format buffer
the first 2*(sectors/track) bytes contain F,N for each sector
F = 00 for good sector, 80h for bad sector
N = sector number
CH = cylinder number (bits 8,9 in high bits of CL)
CL = sector number
DH = head
DL = drive
Return: AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - FIXED DISK - FORMAT DRIVE STARTING AT GIVEN TRACK (XT,PORT)
AH = 07h
AL = interleave value (XT only)
ES:BX = 512-byte format buffer, see AH=6 above
CH = cylinder number (bits 8,9 in high bits of CL)
CL = sector number
DH = head
DL = drive
Return: AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - DISK - GET CURRENT DRIVE PARAMETERS (XT,AT,XT286,CONV,PS)
AH = 08h
DL = drive number
Return: CF set on error
AH = status code (see AH=1 above)
DL = number of consecutive acknowledging drives
DH = maximum value for head number
CL = maximum value fo sector number
CH = maximum value for cylinder number
-----------------------------------------------------------
INT 13 - FIXED DISK - INITIALIZE TWO FIXED DISK BASE TABLES (XT,AT,XT286,PS)
AH = 09h
Return: CF set on error
AH = status code (see AH=1 above)
INT 41h points to table for drive 0
INT 46h points to table for drive 1
-----------------------------------------------------------
INT 13 - FIXED DISK - READ LONG (XT,AT,XT286,PS)
AH = 0Ah
DL = drive ID
DH = head
CH = cylinder (bits 8,9 in high bits of CL)
CL = sector
ES:BX = pointer to buffer to fill
Return: CF set on error
AH = status code (see AH=1 above)
Note: used for diagnostics only on PS/2 systems
-----------------------------------------------------------
INT 13 - FIXED DISK - WRITE LONG (XT,AT,XT286,PS)
AH = 0Bh
DL = drive ID
DH = head
CH = cylinder (bits 8,9 in high bits of CL)
CL = sector
ES:BX = pointer to buffer containing data
Return: CF set on error
AH = status code (see AH=1 above)
Note: used for diagnostics only on PS/2 systems
-----------------------------------------------------------
INT 13 - FIXED DISK - SEEK TO CYLINDER (XT,AT,XT286,PS)
AH = 0Ch
DL = drive ID
DH = head
CH = cylinder (bits 8,9 in high bits of CL)
Return: CF set on error
AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - FIXED DISK - ALTERNATE DISK RESET (XT,PORT,AT,XT286,PS)
AH = 0Dh
DL = drive ID
Return: CF set on error
AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - FIXED DISK - READ SECTOR BUFFER (XT,PORT,PS)
AH = 0Eh
AL = number of sectors
CH = cylinder (bits 8,9 in top two bits of CL)
CL = sector number
DH = head number
DL = drive number
ES:BX = pointer to buffer
Return: AL = number of sectors actually transferred
AH = status code (see AH=1 above)
Note: used for diagnostics only on PS/2 systems
-----------------------------------------------------------
INT 13 - FIXED DISK - WRITE SECTOR BUFFER (XT,PORT,PS)
AH = 0Fh
AL = number of sectors
CH = cylinder (bits 8,9 in top two bits of CL)
CL = sector number
DH = head number
DL = drive number
ES:BX = pointer to buffer
Return: AL = number of sectors actually transferred
AH = status code (see AH=1 above)
Note: used for diagnostics only on PS/2 systems
-----------------------------------------------------------
INT 13 - FIXED DISK - TEST FOR DRIVE READY (XT,AT,XT286,PS)
AH = 10h
DL = drive ID
Return: CF set on error
AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - FIXED DISK - RECALIBRATE DRIVE (XT,PORT,AT,XT286,PS)
AH = 11h
DL = drive ID
Return: CF set on error
AH = status code (see AH=1 above)
-----------------------------------------------------------
INT 13 - FIXED DISK - CONTROLER RAM DIAGNOSTIC (XT,PORT,PS)
AH = 12h
Return: AH = status code (see AH=1 above)
Note: used for diagnostics only on PS/2 systems
-----------------------------------------------------------
INT 13 - FIXED DISK - DRIVE DIAGNOSTIC (XT,PORT,PS)
AH = 13h
Return: AH = status code (see AH=1 above)
Note: used for diagnostics only on PS/2 systems
-----------------------------------------------------------
INT 13 - FIXED DISK - CONTROLLER DIAGNOSTICS (XT,PORT,AT,XT286,PS)
AH = 14h
Return: CF set on error
AH = status code (see AH=1 above)
Note: used for diagnostics only on PS/2 systems
-----------------------------------------------------------
INT 13 - DISK - GET TYPE (AT,XT2,XT286,CONV,PS)
AH = 15h
DL = drive ID
Return: AH = disk type
0 = disk not there
1 = floppy, no change detection present
2 = floppy with change detection
3 = fixed disk
CX:DX = number of 512-byte sectors
-----------------------------------------------------------
INT 13 - DISK - CHANGE OF DISK STATUS (AT,XT2,XT286,CONV,PS)
AH = 16h
DL = drive to check
Return: AH = disk change status
0 = no disk change
6 = disk changed
-----------------------------------------------------------
INT 13 - DISK - SET TYPE (AT,XT2,XT286,CONV,PS)
AH = 17h
AL = disk type
00 = no disk
01 = regular disk in regular drive
02 = regular disk in high-capacity drive
03 = high-capacity disk in high-capacity drive
DL = drive ID
-----------------------------------------------------------
INT 13 - DISK - SET MEDIA TYPE FOR FORMAT (AT model 3x9,XT2,XT286,PS)
AH = 18h
DL = drive number
CH = lower 8 bits of number of tracks
CL = sectors per track (bits 0-5)
top 2 bits of number of tracks (bits 6,7)
Return: AH = 00h requested combination supported
01h function not available
0Ch not supported or drive type unknown
80h there is no disk in the drive
ES:DI = pointer to 11-byte parameter table
-----------------------------------------------------------
INT 13 - FIXED DISK - PARK HEADS (XT286,PS)
AH = 19h
-----------------------------------------------------------
INT 13 - ESDI FIXED DISK - FORMAT UNIT (PS50+)
AH = 1Ah
???
-----------------------------------------------------------
INT 14 - SERIAL I/O - INITIALIZE USART
AH = 00h
AL = initializing parameters
7 - 6 - 5 4 - 3 2 1 - 0
-BAUD RATE- PARITY STOP WORD
BITS LENGTH
000 110 bd 00 none 0-1 10 - 7
001 150 bd 01 odd 1-2 11 - 8
010 300 bd 11 even
011 600 bd
100 1200 bd
101 2400 bd
110 4800 bd
111 9600 bd (4800 on PCjr)
DX = port number
Return: AH = RS-232 status code bits
0: data ready
1: overrun error
2: parity error
3: framing error
4: break detected
5: transmission buffer register empty
6: transmission shift register empty
7: time out--if set, other bits invalid
AL = modem status bits
0: delta Clear-To-Send
1: delta Data-Set-Ready
2: trailing edge of ring detected
3: change in receive line signal detected
4: Clear-To-Send
5: Data-Set-Ready
6: ring detected
7: receive line signal detected
-----------------------------------------------------------
INT 14 - SERIAL I/O - TRANSMIT CHARACTER
AH = 01h
AL = character
DX = port number
Return: AX = port status (see AH = 00h above)
-----------------------------------------------------------
INT 14 - SERIAL I/O - RECEIVE CHARACTER
AH = 02h
Return: AL = character received
AH = RS-232 status code (see AH = 00h above)
-----------------------------------------------------------
INT 14 - SERIAL I/O - GET USART STATUS
AH = 03h
Return: AX = port status code (see AH = 00h above)
-----------------------------------------------------------
INT 14 - SERIAL I/O - EXTENDED INITIALIZE (CONVERTIBLE???,PS)
AH = 04h
AL = break status
0 if break
1 if no break
BH = parity
0 no parity
1 odd parity
2 even parity
3 stick parity odd
4 stick parity even
BL = number of stop bits
0: one stop bit
1: two stop bits (1.5 if 5 bit word length)
CH = word length
0: 5 bits
1: 6 bits
2: 7 bits
3: 8 bits
CL = baud rate
0: 110
1: 150
2: 300
3: 600
4: 1200
5: 2400
6: 4800
7: 9600
8: 19200
Return: AX = port status code (see AH = 00h above)
-----------------------------------------------------------
INT 14 - SERIAL I/O - EXTENDED COMMUNICATION PORT CONTROL (CONVERTIBLE???,PS)
AH = 05h
AL = 0 read modem control register
Return: BL = modem control register (see below)
AH = status
AL = 1 write modem control register
BL = modem control register
bit 0: data terminal ready
bit 1: request to send
bit 2: OUT1
bit 3: OUT2
bit 4: LOOP
bits 5-7 reserved
Return: AH = status
-----------------------------------------------------------
INT 15 - CASSETTE - TURN ON MOTOR (PC,Jr)
AH = 00h
Return: motor turned on
-----------------------------------------------------------
INT 15 - CASSETTE - TURN OFF MOTOR (PC,Jr)
AH = 01h
Return: motor turned off
-----------------------------------------------------------
INT 15 - CASSETTE - READ DATA BLOCKS (PC,Jr)
AH = 02h
CX = count of bytes
ES:BX = pointer to data area
Return: CF set on error
DX = count of bytes read
ES:BX = pointer past last byte read
-----------------------------------------------------------
INT 15 - CASSETTE - WRITE DATA BLOCKS (PC,Jr)
AH = 03h
CX = count of bytes to write
ES:BX = pointer to data area
Return: ES:BX = pointer past last byte written
-----------------------------------------------------------
Int 15 - SYSTEM - FORMAT UNIT PERIODIC INTERRUPT (PS ESDI drives only)
AH = 0Fh
???
Return: ???
-----------------------------------------------------------
INT 15 - TopView - "PAUSE" - GIVE UP CPU TIME
AX = 1000h
Return: after other processes run
-----------------------------------------------------------
INT 15 - TopView - "GETMEM" - ALLOCATE "SYSTEM" MEMORY
AX = 1001h
BX = number of bytes to allocate
Return: ES:DI = pointer to block of memory
-----------------------------------------------------------
INT 15 - TopView - "PUTMEM" - DEALLOCATE "SYSTEM" MEMORY
AX = 1002h
ES:DI = pointer to previously allocated block
Return: block freed
-----------------------------------------------------------
INT 15 - TopView - "PRINTC" - DISPLAY CHARACTER/ATTRIBUTE ON SCREEN
AX = 1003h
BH = attribute
BL = character
DX = segment of object handle for window
Note: BX=0 does not display anything, it only positions the hardware cursor
-----------------------------------------------------------
INT 15 - DESQview (TopView???) - UNIMPLEMENTED IN DV 2.00
AH = 10h
AL = 04h thru 12h
Return: pops up "Programming error" window in DV 2.00
-----------------------------------------------------------
INT 15 - TopView - "GETBIT" - DEFINE A 2ND-LEVEL INTERRUPT HANDLER
AX = 1013h
ES:DI = pointer to FAR service routine
Return: BX = bit mask indicating which bit was allocated
0 if no more bits available
-----------------------------------------------------------
INT 15 - TopView - "FREEBIT" - UNDEFINE A 2ND-LEVEL INTERRUPT HANDLER
AX = 1014h
BX = bit mask from INT 15/AX=1013h
-----------------------------------------------------------
INT 15 - TopView - "SETBIT" - SCHEDULE ONE OR MORE 2ND-LEVEL INTERRUPTS
AX = 1015h
BX = bit mask for interrupts to post
Return: indicated routines will be called at next ???
-----------------------------------------------------------
INT 15 - TopView - "ISOBJ" - VERIFY OBJECT HANDLE
AX = 1016h
ES:DI = possible object handle
Return: BX = 0 if ES:DI is a valid object handle
-1 if ES:DI is not
-----------------------------------------------------------
INT 15 - DESQview (TopView???) - UNIMPLEMENTED IN DV 2.00
AX = 1017h
Return: pops up "Programming error" window in DV 2.00
-----------------------------------------------------------
INT 15 - TopView - "LOCATE" - FIND WINDOW AT A GIVEN SCREEN LOCATION
AX = 1018h
BH = column
BL = row
ES = segment of object handle???
(0 = use default)
Return: ES = segment of object handle for window which is visible at the
indicated position
-----------------------------------------------------------
INT 15 - TopView - "SOUND" - MAKE TONE
AX = 1019h
BX = frequency in Hertz
CX = duration in clock ticks (18.2 ticks/sec)
Return: immediately, tone continues to completion
Notes: if another tone is already playing, the new tone does not start until
completion of the previous one. In DV 2.00, it is possible to enqueue
about 32 tones before the process is blocked until a note completes.
in DV 2.00, the lowest tone allowed is 20 Hz
-----------------------------------------------------------
INT 15 - TopView - "OSTACK" - SWITCH TO TASK'S INTERNAL STACK
AX = 101Ah
Return: stack switched
-----------------------------------------------------------
INT 15 - TopView - "BEGINC" - BEGIN CRITICAL REGION
AX = 101Bh
Return: task-switching temporarily disabled
Note: will not task-switch until END CRITICAL REGION (AX = 101Ch) called
-----------------------------------------------------------
INT 15 - TopView - "ENDC" - END CRITICAL REGION
AX = 101Ch
Return: task-switching enabled
-----------------------------------------------------------
INT 15 - TopView - "STOP" - STOP TASK
AX = 101Dh
ES = segment of object handle for task to be stopped
(== handle of main window for that task)
Return: indicated task will no longer get CPU time
-----------------------------------------------------------
INT 15 - TopView - "START" - START TASK
AX = 101Eh
ES = segment of object handle for task to be started
(== handle of main window for that task)
Return: indicated task is started up again
-----------------------------------------------------------
INT 15 - TopView - "DISPEROR" - POP-UP ERROR WINDOW
AX = 101Fh
BX = bit fields
bits 0-12: number of characters to display
bits 13,14: which mouse button may be pressed to remove window
00 = either
01 = left
10 = right
11 = either (maybe should read "both" or "center"???)
bit 15: beep if 1
DS:DI = pointer to text of message
CH = width of error window (0 = default)
CL = height of error window (0 = default)
DX = segment of object handle
Return: BX = ???
Note: window remains on-screen until ESC or indicated mouse button is pressed
-----------------------------------------------------------
INT 15 - DESQview (TopView???) - UNIMPLEMENTED IN DV 2.00
AX = 1020h
Return: pops up "Programming error" window in DV 2.00
-----------------------------------------------------------
INT 15 - TopView - "PGMINT" - INTERRUPT ANOTHER TASK
AX = 1021h
BX = segment of object handle for task to interrupt
DX:CX = address of FAR routine to jump to (next time task is run???)
Return: nothing???
Note: the current ES, DS, SI, DI, and BP are passed to the FAR routine
-----------------------------------------------------------
INT 15 - TopView - "GETVER" - GET VERSION
AX = 1022h
BX = 0
Return: BX nonzero, TopView or compatible loaded
(BL = major version, BH = minor version)
Notes: TaskView returns BX = 0001h, DESQview 2.0 returns BX = 0A01h
-----------------------------------------------------------
INT 15 - TopView - "POSWIN" - POSITION WINDOW
AX = 1023h
BX = segment of object handle for parent window within which to
position the window (0 = full screen)
DL = bit flags
bits 0,1: horizontal position
00 = current
01 = center
10 = left
11 = right
bits 2,3: vertical position
00 = current
01 = center
10 = top
11 = bottom
bit 4: don't redraw screen if set
bits 5-7 not used
ES = segment of object handle for window
Return: ???
-----------------------------------------------------------
INT 15 - TopView - "GETBUF" - GET VIRTUAL SCREEN INFO
AX = 1024h
BX = segment of object handle for window
(0 = use default)
Return: ES:DI = address of virtual screen
CX = size of virtual screen in bytes
DL = 0 ???
1 ???
-----------------------------------------------------------
INT 15 - TopView - "USTACK" - SWITCH BACK TO USER'S STACK
AX = 1025h
Return: stack switched back
Note: call only after INT 15h/AX=101Ah
-----------------------------------------------------------
INT 15 - DESQview (TopView???) - UNIMPLEMENTED IN DV 2.00
AH = 10h
AL = 26h thru 2Ah
Return: pops up "Programming error" window in DV 2.00
-----------------------------------------------------------
INT 15 - DESQview (TopView???) - "POSTTASK"??? - AWAKEN TASK ???
AX = 102Bh
BX = segment of object handle for task's OBJECTQ ???
Return: nothing
Note: calls INT 15/AH=12/BX=0506
-----------------------------------------------------------
INT 15 - DESQview (TopView???) - SET .PIF ???
AX = 102Ch
BX = number of bytes to copy
>416 changed to 367, then values <= 369 get some additional code
ES:DI = pointer to contents of .PIF file ???
Return: BX = ???
-----------------------------------------------------------
INT 15 - DESQview (TopView???) - ???
AX = 102Dh
BL = subfunction
00h
01h
02h
Return: ???
-----------------------------------------------------------
INT 15 - TopView commands
AH = 11h
AL = various
Note: in DESQview 2.00, these function calls are identical to AH=DEh, so
see those below
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "HANDLE" - RETURN OBJECT HANDLE
AH = 12h
BH = 00h
BL = which handle to return
00h handle in DWORD on top of stack
01h current task's window handle
02h given task's mailbox handle (task's handle on stack)
03h current task's mailbox handle
04h given task's keyboard handle (task's handle on stack)
05h current task's keyboard object handle
06h given task's OBJECTQ handle (task's handle on stack)
07h current task's OBJECTQ handle
08h /
thru > returns 0000:0000
10h /
Return: DWORD on top of stack is object handle
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "NEW" - CREATE NEW OBJECT
AH = 12h
BH = 01h
BL = object
00h handle is DWORD on top of stack
01h use task's window handle
takes 8 DWORD parameters on stack
02h given task's mailbox (task's handle on top of stack)
03h current task's mailbox
04h given task's keyboard (task's handle on top of stack)
05h current task's keyboard object
08h WINDOW class
takes 8 DWORD parameters on stack
09h MAILBOX class
0Ah KEYBOARD class
0Bh TIMER object (counts down 32-bit time in 10ms increments)
0Fh POINTER object
10h PANEL object
Return: DWORD on top of stack is new object handle
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "FREE" - FREE AN OBJECT
AH = 12h
BH = 02h
BL = object
00h handle in DWORD on top of stack
window: close window and free
timer: free timer
panel: free panel object
pointer: free pointer
01h task's window handle - kills task, never returns
02h given task's mailbox (task's handle on top of stack)
03h current task's mailbox
04h given task's keyboard (task's handle on top of stack)
05h current task's keyboard object
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "ADDR" - GET OBJECT HANDLE
AH = 12h
BH = 03h
BL = object
00h handle in DWORD on top of stack
02h sender of last msg read from mailbox (task's handle on stack)
03h sender of last msg read from current task's mailbox
Return: DWORD on stack is handle
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "DIR" - GET PANEL FILE DIRECTORY
AH = 12h
BX = 0300h
STACK: DWORD handle of panel object
Return: ???
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "READ" - GET NEXT RECORD
AH = 12h
BH = 04h
BL = object
00h handle is DWORD on top of stack
window: read next logical line
timer: wait for timer to expire
pointer: wait for next message
01h read the next logical line from task's default window
02h get next message from mailbox (task's handle on top of stack)
03h get next message from current task's mailbox
04h get the next input from keyboard (handle on top of stack)
05h get the next input from task's default keyboard
06h wait for input from any object in OBJECTQ (handle on stack)
07h wait for input from any object in task's default OBJECTQ
Return: STACK: DWORD number of bytes
DWORD address
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "APPLY" - WRITE PANEL TO WINDOW
AH = 12h
BX = 0400h
STACK: DWORD handle of panel object
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "WRITE" - WRITE STRING TO OBJECT
AH = 12h
BH = 05h
BL = object
00h handle is DWORD on top of stack
window: write string
timer: start timer to end at a specified time
pointer: move pointer icon to specified position
01h write string to task's default window
02h send message by value/status=0 to mbox (task's handle on stack)
03h send message by value/status=0 to current task's mailbox
04h add input buffer to KEYBOARD queue (handle on top of stack)
05h add input buffer to task's default KEYBOARD queue
06h add an object to OBJECTQ (handle on top of stack)
07h add an object to task's default OBJECTQ
STACK: DWORD object handle if handle passed on stack
DWORD total length of string (high word == 0)
DWORD address of string to display
Note: service routine will pop stack
-----------
IF OBJECT IS A WINDOW, THEN
Return: indicated actions performed
a. non-control characters are displayed
b. CR/LF/BS/Tab cause the usual cursor movement
c. ESC starts a data structure with additional commands
Data Structure:
MAGIC DB 1Bh
MODE DB ? ; 00h, 01h, 10h, 14h-1Fh legal
LENGTH DW ? ; length of remainder in bytes
var-length fields follow, each an OPCODE followed by
zero or more args
MODE 00h (set or display values) "WINDOW STREAM"
Opcodes:args
00h display 20h blanks with the default attribute
01h-1Fh display OPCODE blanks with the default attribute
20h display char with default attribute 20h times
BYTE char to repeat
21h-3Fh display char with default attribute OPCODE-20h times
BYTE char to repeat
40h display 20h blanks with specified attribute
BYTE attribute of blanks
41h-5Fh display OPCODE-40h blanks with specified attribute
BYTE attribute of blanks
60h display next 20h characters
20h BYTES characters to display
61h-7Fh display next OPCODE-60h characters
N BYTES characters to display
80h-87h display N blanks with default attribute
BYTE low 8 bits of 11-bit count (high 3 in low 3 bits of OPCODE)
[000h means 800h]
88h-8Fh display N copies of the character
BYTE low 8 bits of 11-bit count (high 3 in low 3 bits of OPCODE)
[000h means 800h]
BYTE character to repeat
90h-97h display N blanks with specified attribute
BYTE low 8 bits of 11-bit length (high 3 in low 3 bits of OPCODE)
[000h means 800h]
BYTE attribute
98h-9FH display string at logical cursor pos
BYTE low 8 bits of 11-bit length (high 3 in low 3 bits of OPCODE)
[000h means 800h]
N BYTES string to display
A0h set logical cursor row
BYTE row number (0 is top)
A1h set logical cursor column
BYTE column number (0 is leftmost)
A2h ???
BYTE ???
A3h ???
BYTE ???
A4h set row of physical window position
BYTE line
A5h set column of physical window position
BYTE column
A6h set height of physical window
BYTE #rows
A7h set width of physical window
BYTE #columns
A8h set viewport row
BYTE row
A9h set viewport column
BYTE column
AAh set virtual screen height
BYTE rows
ABh set virtual screen width
BYTE columns
ACh-AEh unused
AFh ???
BYTE ??? (ANDed with current value of something)
B0h move logical cursor down
BYTE #rows (signed, negative values move up)
B1h move logical cursor right
BYTE #cols (signed, negative values move left)
B2h ???
BYTE ??? (signed)
B3h ???
BYTE ??? (signed)
B4h shift window down
BYTE #lines (signed)
B5h shift window right
BYTE #columns (signed)
B6h expand physical window vertically
BYTE #lines (signed)
B7h expand physical window horizontally
BYTE #columns (signed)
B8h adjust viewport row
BYTE #rows (signed)
B9h adjust viewport column
BYTE #columns (signed)
BAh adjust virtual screen height
BYTE #rows to increase (signed)
BBh adjust virtual screen width
BYTE #cols to increase (signed)
BCh-BFh unused
C0h set logical cursor position
BYTE row number (0 is top border)
BYTE column number (0 is left border)
C1h ???
BYTE ???
BYTE ???
C2h set window pos
BYTE upper left row (no top border if 0)
BYTE upper left column (no left border if 0)
C3h set current window size
BYTE #rows
BYTE #cols
C4h set upper left corner of viewport (portion of virtual screen
displayed in window)
BYTE row
BYTE column
C5h set size of virtual screen
BYTE #rows
BYTE #cols
C6h unused
C7h unused
C8h set logical cursor relative to current position
BYTE number of rows to move down (signed)
BYTE number of columns to move right (signed)
C9h ???
BYTE ???
BYTE ???
CAh set window pos relative to current position
BYTE number of rows to shift down (signed)
BYTE number of columns to shift right (signed)
CBh set window size relative to current size
BYTE number of rows to expand (signed)
BYTE number of cols to expand (signed)
CCh shift viewport relative to current position
BYTE rows to shift (signed)
BYTE cols to shift (signed)
CDh resize virtual screen (guess)
BYTE #rows to expand (signed)
BYTE #cols to expand (signed)
CEh clear ???
CFh set ???
D0h turn on ??? (default)
D1h turn off ???
D2h turn on ???
D3h turn off ??? (default)
D4h window is visible
D5h window is hidden
D6h window has frame
D7h window unframed
D8h turn on ??? (default)
D9h turn off ???
DAh use logical attributes, which may be remapped
attributes
1 normal text
2 highlighted normal text
3 help text
4 highlighted help text
5 error message
6 highlighted error message
7 emphasized text
8 marked text
others???
DBh use physical attributes for characters
DCh enable special actions for control characters (default)
DDh disable special control char handling, all chars displayable by
BIOS TTY call
DEh write both character and attribute (default)
DFh write character only, leave attribute untouched
E0h repeat following commands
BYTE number of times
E1h end of commands to repeat, start repeating them
E2h set color
BYTE color
E3h clear virtual screen
E4h redraw window
E5h ???
BYTE ???
E6h create new window and perform rest of manipulations in new window
BYTE number of rows
BYTE number of columns
Return: DWORD object handle returned on stack at end
E7h unused
E8h ???
BYTE ???
BYTE ???
additional args???
E9h ???
BYTE ???
BYTE ???
additional args???
EAh ???
BYTE ???
BYTE ???
additional args???
EBh ???
BYTE ???
BYTE ???
additional args???
ECh ???
BYTE ???
BYTE count of remaining args / counted string maybe???
N BYTES remaining args /
EDh ???
BYTE ???
BYTE ???
var-length args
EEh same as EDh, but ???
BYTE ???
BYTE ???
var-length args
EFh set window name
BYTE length of name
N BYTES name
F0h clear input field to blanks
BYTE field number
F1h fill input field with character
BYTE field number
BYTE char
F2h set color of input field
BYTE field number (1-N)
BYTE attribute
F3h set initial contents of input field
BYTE field number (1-N)
N BYTES enough chars to exactly fill field as defined by op FFh
F4h position cursor to specific input field
BYTE field number (1-N)
F5h change field table entry
BYTE field number
7-8 BYTEs field table entry (see FFh)
F6h set field type??? (guess)
BYTE field number
BYTE type???
F7h ???
STRING??? (I saw 20h 20h 20h 20h)
F8h ???
BYTE field number
additional args???
F9h ???
BYTE field number
additional args???
FAh ???
BYTE field number
additional args???
FBh ???
BYTE field number
additional args???
FCh set field table header??? (guess)
BYTE field number
BYTE ???
6 BYTES ???
additional args???
FDh ???
no args???
FEh ??? (no args)
FFh set up input fields
table header
BYTE number of fields
BYTE screen type ??? (I see 47h, 52h, 53h, 55h, 57h, and 5Bh)
WORD ??? (I see 0 always)
BYTE color of field currently pointed to
BYTE color of input fields which have been selected
the field table entries, one for each field
BYTE start row
BYTE start column
BYTE end row
BYTE end column
BYTE field type (A0h allows user entry, 00h/40h don't)
80h is a fill-in field
C0h is a menu selection
BYTE modifier
if type is 80h, then bit flags to determine behavior
bit 7 if set, beep when field is full
bit 6 move to next field when current field is full
bit 5 if set, enter text from right end (for numbers)
bit 4 if set, force input to uppercase
bit 3 if set, clear old contents on first keystroke
bit 2,1,0 ???
if type is C0h, key to press to activate menu sel
00h if have to point-and-click
BYTE ???
BYTE second key for activating menu selection if field type is
C0h (0 = only single key). Only present if SCREEN TYPE
is 5Bh
MODE 01h "QUERY STREAM" (valid only for those opcodes listed here)
A0h return logical cursor row in next byte
A1h return logical cursor column in next byte
A2h
A3h
A4h return row of physical window origin in next byte
A5h return column of physical window origin in next byte
A6h return height of physcial window in next byte
A7h return width of physical window in next byte
A8h return row of viewport origin in next byte
A9h return column of viewport origin in next byte
AAh return height of virtual screen in next byte
ABh return width of virtual screen in next byte
AFh return ??? in next byte
C0h return current logical cursor position in next two bytes
C1h return ??? in next two bytes
C2h return current window position in next two bytes
C3h return current window size in next two bytes
C4h return current viewport origin in next two bytes
C5h return current virtual screen size in next two bytes
D0h / overwritten with D0h if ??? on
D1h / D1h if ??? off
D2h / overwritten with D2h if ??? on
D3h / D3h if ??? off
D4h / overwritten with D4h if window visible
D5h / D5h if window hidden
D6h / overwritten with D6h if window has frame
D7h / D7h if window unframed
D8h / overwritten with D8h if ??? on
D9h / D9h if ??? off
DAh / overwritten with DAh if using logical attributes
DBh / DBh if using physical attributes
DCh / overwritten with DCh if TTY control char interpretation on
DDh / DDh if TTY control char interpretation off
DEh / overwritten with DEh if writing both characters and attributes
DFh / DFh if leaving attributes untouched
E2h return current color in next byte
ECh
EDh
EEh
EFh return current window name
BYTE max length of returned name
N BYTES buffer to hold window name
F3h return contents of input field
BYTE field number
N BYTES buffer to hold field contents (size exactly equal to field
size)
F5h get field table entry
BYTE field number
7-8 BYTES buffer to hold field table entry
F6h get type of a field??? (guess)
BYTE field number
BYTE type???
FCh get field table header??? (guess)
BYTE field number
BYTE ???
6 BYTES ???
additional args???
MODE 10h "MANAGER STREAM" (valid only for opcodes listed here)
00h allow window to be moved horizontally
01h allow window to be moved vertically
02h allow window to change width
03h allow window to change height
04h allow window to be scrolled horizontally
05h allow window to be scrolled vertically
06h allow "Close Window" menu selection
07h allow window to be hidden
08h allow "Mark" menu
0Eh allow "Scissors" menu
10h allow DESQview main menu to be popped up
11h allow "Switch Windows" menu
12h allow "Open Window" menu
13h allow "Quit" menu selection
20h-33h opposite of 00h-13h, disallow specified action
40h notify if horizontal position of window changes
41h notify if vertical position of window changes
42h notify if width of window changes
43h notify if height of window changes
44h notify if window scrolled horizontally
45h notify if window scrolled vertically
46h notify if window is closed--program has to clean up and exit itself
47h notify if window is hidden
48h notify if "?" on main menu selected
49h notify if ???
4Ah notify if window is swapped out or hidden
4Bh notify if ???
4Ch notify if video mode changes
4Dh notify if "Scissors" menu "Cut" option selected
4Eh notify if "Scissors" menu "Copy" option selected
4Fh notify if "Scissors" menu "Paste" option selected
50h notify if DESQview main menu popped up
51h notify if "Switch" menu selected
60h-71h opposite of 40h-51h: don't notify on specified event
84h
85h
86h disable background operation
87h enable running in background
88h set minimum size of physical window
BYTE rows
BYTE columns
89h set maximum size of physical window
BYTE rows
BYTE cols
8Ah set primary asynchronous notification routine
DWORD address of routine, 0000:0000 means none
on entry ES:DI = handle of window, DS:SI is secondary routine
routine should restore all registers before returning
8Bh set secondary async notification routine
DWORD address of routine, passed to primary routine in DS:SI,
rather than called directly
AEh
AFh ???
BYTE ???
BCh
BDh opposite of BCh
BEh
BFh opposite of BEh
C0h move current window in front of all other windows
C1h ???
C2h move current window in front of all other windows
C3h ??? (like C4h, but uses defaults)
C4h ???
BYTE ???
BYTE ???
C5h hide current window
C6h ???
C7h hide all windows for this process and switch to previous process
C8h hide all windows for this process and switch to previous process
C9h switch to previous process
CAh move current window back behind other windows for this process
CBh ???
CCh closes current window???
CEh reorder windows
DWORD pointer to null-terminated list of words
each word is segment of object handle for a window
MODES 14h to 1Fh ("user streams"???)
normally NOPs, but may be defined (don't know how yet) to invoke FAR
routines, one for each mode number
on entry to handler,
DS:SI = first byte of actual stream (not header)
CX = #bytes in stream
ES:DI = window's handle???
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "SIZEOF" - GET OBJECT SIZE
AH = 12h
BH = 08h
BL = object
00h handle in DWORD on top of stack
timer: elapsed time since timer started
pointer: number of messages queued to pointer object
panel: number of panels in panel file
01h total chars in current task's default window
02h number of messages in task's mailbox (task's handle on stack)
03h number of messages in current task's mailbox
04h number of input buffers queued in task's kbd (handle on stack)
05h number of input buffers queued for current task's default kbd
06h number of objects queued in OBJECTQ (task's handle on stack)
07h number of objects queued in current task's OBJECTQ
Return: DWORD on stack is result
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "LEN" - GET OBJECT LENGTH
AH = 12h
BH = 09h
BL = object
00h handle in DWORD on top of stack
window: chars/line
timer: timer remaining before timer expires
01h number of chars/line in current task's default window
Return: DWORD on top of stack is length
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "ADDTO" - SET OBJECT BITS
AH = 12h
BH = 0Ah
BL = object
00h handle is DWORD on top of stack
window: write characters and attributes
timer: start timer for specified interval
pointer: set control flags
01h write characters and attributes to task's default window
02h send message/status by value to mailbox (task's handle on stack)
03h send message/status by value to current task's default mailbox
04h set control flags on KEYBOARD object (handle on top of stack)
05h set control flags on task's default KEYBOARD object
STACK: (if mailbox) DWORD status
DWORD length of message
DWORD address
(otherwise) DWORD bits to set
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "SUBFROM" - RESET OBJECT BITS
AH = 12h
BH = 0Bh
BL = object
00h handle is DWORD on top of stack
pointer: reset control flags
01h write attributes only to task's default window
02h send message/status by reference to box (task's handle on stack)
03h send message/status by reference to current task's mailbox
04h clear control flags on KEYBOARD object (handle on top of stack)
05h clear control flags on task's default KEYBOARD object
06h remove specific object from OBJECTQ (handle on top of stack)
07h remove specific object from task's default OBJECTQ
STACK: DWORD indicates which bits to clear
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "OPEN" - OPEN OBJECT
AH = 12h
BH = 0Ch
BL = object
00h handle is DWORD on top of stack
timer: open
pointer: start taking input for window
panel: associate with a panel file
01h fill task's default window with given character
02h open given task's mailbox for input (task's handle on stack)
03h open current task's mailbox
04h attach a KEYBOARD to a window (handle on top of stack)
05h attach task's default KEYBOARD to a window
06h open a task's OBJECTQ (task's handle on top of stack)
07h open current task's OBJECTQ
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "CLOSE" - CLOSE OBJECT
AH = 12h
BH = 0Dh
BL = object
00h handle is DWORD on top of stack
timer: close
pointer: stop taking input
panel: close
02h close given task's mailbox (task's handle on top of stack)
03h close task's default mailbox
04h close KEYBOARD object (handle on top of stack)
05h close task's default KEYBOARD
06h close givent task's OBJECTQ (task's handle on top of stack)
07h close current task's OBJECTQ
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "ERASE" - ERASE OBJECT
AH = 12h
BH = 0Eh
BL = object
00h handle is DWORD on top of stack
window: clear
timer: cancel current interval
pointer: discard all pending messages
01h clear task's default window
02h discard all queued messages in mailbox (handle on top of stack)
03h discard all queued messages in current task's default mailbox
04h discard all input queued to KEYBOARD (handle on top of stack)
05h discard all input queued to task's default KEYBOARD
06h remove all objects from OBJECTQ (task's handle on top of stack)
07h remove all objects from current task's OBJECTQ
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "STATUS" - GET OBJECT STATUS
AH = 12h
BH = 0Fh
BL = object
00h handle is DWORD on top of stack
timer: is it running?
pointer: return status of last message
panel: verify success of last OPEN or APPLY
02h return status of last msg READ from mailbox (handle on stack)
03h return status of last msg READ from task's default mailbox
04h get scan code for last key read from KEYBOARD (handle on stack)
05h get scan code for last key read from task's default KEYBOARD
06h return whether OBJECTQ is open or not (handle on top of stack)
07h return whether task's default OBJECTQ is open or not
Return: DWORD on top of stack is status
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "EOF" - GET OBJECT EOF STATUS
AH = 12h
BH = 10h
BL = object
00h handle is DWORD on top of stack
01h returns TRUE if logical cursor past end of task's def window
Return: DWORD on top of stack is status
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "AT" - POSITION OBJECT CURSOR
AH = 12h
BH = 11h
BL = object
00h handle is DWORD on top of stack
01h position logical cursor on task's default window
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "SETSCALE" - SET POINTER SCALE FACTOR
AH = 12h
BX = 1100h
STACK: DWORD object handle for pointer object
DWORD ???
DWORD ???
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "READN" - GET NEXT N OBJECT BYTES
AH = 12h
BH = 12h
BL = object
00h handle is DWORD on top of stack
01h read next N chars/attributes on task's default window
STACK: DWORD count
Return: STACK: DWORD count actually read
DWORD address
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "GETSCALE" - GET POINTER SCALE FACTOR
AH = 12h
BX = 1200h
STACK: DWORD object handle for pointer
Return: STACK: DWORD ???
DWORD ???
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "REDRAW" - REDRAW WINDOW
AH = 12h
BH = 13h
BL = object
00h DWORD on top of stack is handle for window to redraw
01h redraw task's default window
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "SETICON" - SPECIFY POINTER ICON
AH = 12h
BX = 1300h
STACK: DWORD object handle for pointer
???
-----------------------------------------------------------
INT 15 - TopView - SEND MESSAGE - "SETESC" - SET ESCAPE ROUTINE ADDRESS
AH = 12h
BH = 14h
BL = message modifier
00h handle is DWORD on top of stack
04h intercept keystrokes from KEYBOARD to a window (handle on stack)
05h intercept keystrokes from task's default KEYBOARD to a window
-----------------------------------------------------------
INT 15 - PRINT.COM - ??? (AT,XT286,PS50+)
AH = 20h
AL = subfunction
00h ???
01h ???
10h setup of SYSREQ routine (OS hook)
11h completion of SYSREQ function (OS hook)
Note: AL = 0,1 set or reset some flags which affect what PRINT does when it
tries to access the disk
-----------------------------------------------------------
INT 15 - SYSTEM - POWER-ON SELF-TEST ERROR LOG (PS50+)
AH = 21h
???
Return: ???
-----------------------------------------------------------
INT 15 - READ/MODIFY PROFILES (CONVERTIBLE)
AH = 40h
AL = subfunction
0: get system profile in CX and BX
1: set system profile from CX and BX
2: get internal modem profile in BX
3: set internal modem profile from BX
-----------------------------------------------------------
INT 15 - SYSTEM - WAIT ON EXTERNAL EVENT (CONVERTIBLE)
AH = 41h
AL = condition type
bits 0-2: condition to wait for
0 any external event
1 compare and return if equal
2 compare and return if not equal
3 test and return if not zero
4 test and return if zero
bit 3: reserved
bit 4: 1=port address, 0=user byte
bits 5-7: reserved
BH = condition compare or mask value
BL = timeout value times 55 milliseconds
0 means no timeout
DX = I/O port address if AL bit 4 set
ES:DI = pointer to user byte if AL bit 4 clear
-----------------------------------------------------------
INT 15 - SYSTEM - REQUEST POWER OFF (CONVERTIBLE)
AH = 42h
AL = 0 to use system profile
1 to force suspend regardless of system profile
-----------------------------------------------------------
INT 15 - SYSTEM - READ SYSTEM STATUS (CONVERTIBLE)
AH = 43h
Return: AL = status bits
bit 0: LCD detached
bit 1: reserved
bit 2: RS232/parallel adapter powered on
bit 3: internal modem powered on
bit 4: power activated by alarm
bit 5: standby power lost
bit 6: external power in use
bit 7: power low
-----------------------------------------------------------
INT 15 - SYSTEM - (DE)ACTIVATE INTERNAL MODEM POWER (CONVERTIBLE)
AH = 44h
AL = 0 to power off
1 to power on
-----------------------------------------------------------
INT 15 - OS HOOK - KEYBOARD INTERCEPT (AT model 3x9,XT2,XT286,CONV,PS)
AH = 4Fh
AL = scan code
CF set
Return: AL = scan code
CF set
Note: Called by INT 9 handler to translate scan codes
-----------------------------------------------------------
INT 15 - OS HOOK - DEVICE OPEN (AT,XT2,XT286,PS)
AH = 80h
BX = device ID
CX = process type
-----------------------------------------------------------
INT 15 - OS HOOK - DEVICE CLOSE (AT,XT2,XT286,PS)
AH = 81h
BX = device ID
CX = process type
-----------------------------------------------------------
INT 15 - OS HOOK - DEVICE PROGRAM TERMINATE (AT,XT2,XT286,PS)
AH = 82h
BX = device ID
-----------------------------------------------------------
INT 15 - SYSTEM - EVENT WAIT (AT,XT286,CONV,PS)
AH = 83h
AL = subservice
0 = set interval
1 = cancel
ES:BX = pointer to event flag (bit 7 set when interval expires)
CX:DX = number of microseconds to wait (only accurate to 977 us)
Return: CF set if function already busy
-----------------------------------------------------------
INT 15 - SYSTEM - READ JOYSTICK (AT,XT2,XT286,PS)
AH = 84h
DX = subservice
0 get switch settings
Return: AL = switch settings (bits 7-4)
1 read joystick inputs
Return: AX = A(x) value
BX = A(y) value
CX = B(x) value
DX = B(y) value
-----------------------------------------------------------
INT 15 - OS HOOK - SYSTEM REQUEST KEY PRESSED (AT,XT2,XT286,CONV,PS)
AH = 85h
AL = 0 press
= 1 release
Note: called by keyboard decode routine
-----------------------------------------------------------
INT 15 - SYSTEM - WAIT (AT,XT2,XT286,CONV,PS)
AH = 86h
CX,DX = number of microseconds to wait (only accurate to 977 us)
Return: after wait elapses
-----------------------------------------------------------
INT 15 - EXTENDED MEMORY - BLOCK MOVE (AT,XT286,PS)
AH = 87h
CX = number of words to move
ES:SI = pointer to global descriptor table
offset 0h null descriptor (need not be initialized)
8h uninitialized, will be made into GDT descriptor
10h descriptor for source of move
18h descriptor for destination of move
20h uninitialized, used by BIOS
28h uninitialized, will be made into SS descriptor
Return: source copied into destination
-----------------------------------------------------------
INT 15 - EXTENDED MEMORY - GET MEMORY SIZE (AT,XT286,PS)
AH = 88h
Return: AX = memory size
-----------------------------------------------------------
INT 15 - SYSTEM - SWITCH TO VIRTUAL MODE (AT,XT286,PS50+)
AH = 89h
BL = interrupt number of IRQ0 (IRQ1-7 use next 7 interrupts)
BH = interrupt number of IRQ8 (IRQ9-F use next 7 interrupts)
DS:SI = pointer to GDT for protected mode
offset 0h null descriptor
8h GDT descriptor
10h IDT descriptor
18h DS
20h ES
28h SS
30h CS
38h uninitialized, used to build descriptor for BIOS CS
CX = offset into protected-mode CS to jump to
Return: CF set on error
AH = 0FFh error enabling address line 20
-----------------------------------------------------------
INT 15 - OS HOOK - DEVICE BUSY LOOP (AT,XT2,XT286,CONV,PS)
AH = 90h
AL = TYPE CODE
00h: disk
01h: diskette
02h: keyboard
80h: network
ES:BX = NCB
FCh: disk reset
FDh: diskette motor start
FEh: printer
Return: CF set if wait time satisfied
Note: type codes are allocated as follows:
00-7F non-reentrant devices; OS must arbitrate access
80-BF reentrant devices; ES:BX points to a unique control block
C0-FF wait-only calls, no complementary INT 15/AH=91h call
-----------------------------------------------------------
INT 15 - OS HOOK - SET FLAG AND COMPLETE INTERRUPT (AT,XT2,XT286,CONV,PS)
AH = 91h
AL = type code, see AH=90h above
-----------------------------------------------------------
INT 15 - SYSTEM - GET CONFIGURATION (XT after 1/10/86,AT mdl 3x9,CONV,XT286,PS)
AH = C0h
Return: CF = 1 if BIOS doesn't support call
ES:BX pointer to ROM table
byte_count dw ? ; number of bytes following
model db ? ; PC=ff, XT=fe or fb, PCjr = fd, etc, etc
submodel db ? ; distingushes between AT and XT/286, etc.
BIOS_rev db ? ; 0 for first release, 1 for 2nd, etc.
featbyte db ? ; 80h = DMA channel 3 used by hd BIOS
; 40h = 2nd 8259 installed
; 20h = Real-Time Clock installed
; 10h = INT 15h/AH=4Fh called upon INT 9h
; 8h = wait for external event supported
; 4h = extended BIOS area allocated at 640K
; 2h = bus is Micro Channel instead of PC
; 1h reserved
res1 dw 0
res2 dw 0
Note: the 1/10/86 XT BIOS returns an incorrect value for featbyte.
-----------------------------------------------------------
INT 15 - SYSTEM - RETURN EXTENDED-BIOS DATA-AREA SEGMENT ADDRESS (PS)
AH = C1h
???
Return: ???
-----------------------------------------------------------
INT 15 - POINTING DEVICE BIOS INTERFACE (PS)
AH = C2h
???
Return: ???
-----------------------------------------------------------
INT 15 - DESQview - ???
AH = C2h
AL = subfunction
00h ???
BH = ???
01h set something to default values
02h ???
BH = ???
03h ???
BH = ???
04h NOP, points to RET instruction
05h same as 01h, but also takes input value in BH
BH = ???
06h ???
BH = 01h or 02h stored, otherwise ignored
07h ???
ES:BX = pointer to ???
Return: AL = 00h
Note: the values in BH for those functions that take it as input are stored
in different locations for each subfunction
----------------------------------------------------------
INT 15 - ENABLE/DISABLE WATCHDOG TIMEOUT (PS50+)
AH = C3h
???
Return: ???
-----------------------------------------------------------
INT 15 - PROGRAMMABLE OPTION SELECT (PS50+)
AH = C4h
???
Return: ???
-----------------------------------------------------------
INT 15 - DESQview - GET PROGRAM NAME
AX = DE00h
Return: AX = offset into DESQVIEW.DVO of current program:
BYTE length of name
N BYTES name
2 BYTES keys to invoke program (second = 00h if only one key used)
3 BYTES ??? (I see 0 always)
-----------------------------------------------------------
INT 15 - DESQview - UPDATE OPEN MENU???
AX = DE01h
???
Return: nothing
Note: reads DESQVIEW.DVO, disables Open menu if file not in current directory
-----------------------------------------------------------
INT 15 - DESQview - UNIMPLEMENTED IN DV 2.00
AX = DE02h
Return: nothing (NOP in DV 2.00)
-----------------------------------------------------------
INT 15 - DESQview - UNIMPLEMENTED IN DV 2.00
AX = DE03h
Return: nothing (NOP in DV 2.00)
-----------------------------------------------------------
INT 15 - DESQview - GET AVAILABLE COMMON MEMORY
AX = DE04h
Return: BX = bytes of common memory available
CX = largest block available
DX = total common memory in bytes
-----------------------------------------------------------
INT 15 - DESQview - GET AVAILABLE CONVENTIONAL MEMORY
AX = DE05h
Return: BX = K of memory available
CX = largest block available
DX = total conventional memory in K
-----------------------------------------------------------
INT 15 - DESQview - GET AVAILABLE EXPANDED MEMORY
AX = DE06h
Return: BX = K of expanded memory available
CX = largest block available
DX = total expanded memory in K
-----------------------------------------------------------
INT 15 - DESQview - "APPNUM" - GET CURRENT PROGRAM'S NUMBER
AX = DE07h
Return: AX = number of program as it appears on the "Switch Windows" menu
-----------------------------------------------------------
INT 15 - DESQview - GET ???
AX = DE08h
Return: AX = 0 ???
1 ???
-----------------------------------------------------------
INT 15 - DESQview - UNIMPLEMENTED IN DV 2.00
AX = DE09h
Return: nothing (NOP in DV 2.00)
-----------------------------------------------------------
INT 15 - DESQview 2.0 - "DBGPOKE" - DISPLAY CHARACTER ON STATUS LINE
AX = DE0Ah
BL = character
Return: character displayed, next call will display in next position (which
wraps back to the start of the line if off the right edge of screen)
Notes: displays character on bottom line of *physical* screen, regardless
of current size of window (even entirely hidden)
does not know about graphics display modes, just pokes the characters
into display memory
-----------------------------------------------------------
INT 15 - DESQview 2.0 - "APILEVEL" - DEFINE MINIMUM API LEVEL REQUIRED
AX = DE0Bh
BL = API level
>2 pops up "You need a newer version" error window in DV 2.00
BH = ???
Return: ???
-----------------------------------------------------------
INT 15 - DESQview 2.0 - "GETMEM" - ALLOCATE "SYSTEM" MEMORY
AX = DE0Ch
BX = number of bytes
Return: ES:DI = pointer to allocated block
-----------------------------------------------------------
INT 15 - DESQview 2.0 - "PUTMEM" - DEALLOCATE "SYSTEM" MEMORY
AX = DE0Dh
ES:DI = pointer to previously allocated block
Return: nothing
-----------------------------------------------------------
INT 15 - DESQview 2.0 - FIND MAILBOX BY NAME???
AX = DE0Eh
ES:DI = pointer to string
CX = length of name
Return: BX = 0 not found
1 found
DS:SI = object handle???
-----------------------------------------------------------
INT 15 - DESQview 2.0 - ???
AX = DE0Fh
Return: AX and BX destroyed (seems to be bug, weren't saved&restored)
Note: sends a manager stream with opcodes AEh, BDh, and BFh to task's window
-----------------------------------------------------------
INT 15 - DESQview 2.0 - "PUSHKEY" - PUT KEY INTO KEYBOARD INPUT STREAM
AX = DE10h
BH = scan code
BL = character
Return: BX = ??? (sometimes, but not always, same as BX passed in)
Note: a later read will get the keystroke as if it had been typed by the user
-----------------------------------------------------------
INT 15 - DESQview 2.0 - ENABLE/DISABLE AUTOMATIC JUSTIFICATION OF WINDOW
AX = DE11h
BL = 0 viewport will not move automatically
nonzero viewport will move to keep cursor visible
Return: nothing
-----------------------------------------------------------
INT 16 - KEYBOARD - READ CHAR FROM BUFFER, WAIT IF EMPTY
AH = 00h
Return: AH = scan code
AL = character
-----------------------------------------------------------
INT 16 - KEYBOARD - CHECK BUFFER, DO NOT CLEAR
AH = 01h
Return: ZF = 0 character in buffer
AH = scan code
AL = character
ZF = 1 no character in buffer
-----------------------------------------------------------
INT 16 - KEYBOARD - GET SHIFT STATUS
AH = 02h
AL = shift status bits
0 = right shift key depressed
1 = left shift key depressed
2 = CTRL depressed
3 = ALT depressed
4 = SCROLL LOCK active
5 = NUM LOCK active
6 = CAPS LOCK active
7 = INSERT state active
-----------------------------------------------------------
INT 16 - KEYBOARD - SET DELAYS (Jr,AT model 339,XT286,PS)
AH = 03h
AL = subfunction
0 reset typematic (PCjr)
1 increase initial delay (PCjr)
2 increase continuing delay (PCjr)
3 increase both delays (PCjr)
4 turn off typematic (PCjr)
5 Set typematic rate (AT or PS/2)
BH = 00 - 03 for delays of 250ms, 500ms, 750ms, or 1s
BL = 00 - 1F for typematic rates of 30cps down to 2cps
-----------------------------------------------------------
INT 16 - KEYBOARD - KEYCLICK (Jr,CONV)
AH = 04h
AL =
0 click off
1 click on
-----------------------------------------------------------
INT 16 - KEYBOARD - WRITE TO KEYBOARD BUFFER (AT model 339,XT2,XT286,PS)
AH = 05h
CH = scan code
CL = character
Return: AL = 1 if buffer full
-----------------------------------------------------------
INT 16 - KEYBOARD - GET ENHANCED KEYSTROKE (AT model 339,XT2,XT286,PS)
AH = 10h
Return: AH = scan code
AL = character
-----------------------------------------------------------
INT 16 - KEYBOARD - CHECK ENHANCED KEYSTROKE (AT model 339,XT2,XT286,PS)
AH = 11h
Return: ZF = 0 if keystroke available
AH = scan code / meaningless if ZF = 1
AL = character /
ZF = 1 if kbd buffer empty
-----------------------------------------------------------
INT 16 - KEYBOARD - GET ENHANCED SHIFT FLAGS (AT model 339,XT2,XT286,PS)
AH = 12h
Return: AL (same as for AH=02h)
bit 7: Ins ON
bit 6: CapsLock ON
bit 5: NumLock ON
bit 4: ScrollLock ON
bit 3: Either ALT key down
bit 2: Either CTRL key down
bit 1: Left shift key down
bit 0: Right shift key down
AH
bit 7: SysReq key down
bit 6: CapsLock key down
bit 5: NumLock key down
bit 4: ScrollLock key down
bit 3: Right Alt key down
bit 2: Right Ctrl key down
bit 1: Left Alt key down
bit 0: Right Alt key down
-----------------------------------------------------------
INT 17 - PRINTER - OUTPUT CHARACTER
AH = 00h
AL = character
Return: AH = status bits
0 = time out
1 = unused
2 = unused
3 = I/O error
4 = selected
5 = out of paper
6 = acknowledge
7 = not busy
-----------------------------------------------------------
INT 17 - PRINTER - INITIALIZE
AH = 01h
Return: AH = status (see AH = 00h above)
-----------------------------------------------------------
INT 17 - PRINTER - GET STATUS
AH = 02h
Return: AH = status (see AH = 00h above)
-----------------------------------------------------------
INT 18 - TRANSFER TO ROM BASIC
causes transfer to ROM-based BASIC (IBM-PC)
often reboots a compatible; often has no effect at all
-----------------------------------------------------------
INT 19 - DISK BOOT
causes reboot of disk system (no memory test performed)
-----------------------------------------------------------
INT 1A - CLOCK - GET TIME OF DAY
AH = 00h
Return: CX:DX = clock count
AL = 0 if clock was read or written (via AH=0,1)
within the current 24-hour period
Otherwise, AL > 0
-----------------------------------------------------------
INT 1A - CLOCK - SET TIME OF DAY
AH = 01h
CX:DX = clock count
Return: time of day set
-----------------------------------------------------------
INT 1A - CLOCK - READ REAL TIME CLOCK (AT,XT286,CONV,PS)
AH = 02h
Return: CH = hours
CL = minutes
DH = seconds
-----------------------------------------------------------
INT 1A - CLOCK - SET REAL TIME CLOCK (AT,XT286,CONV,PS)
AH = 03h
CH = hours
CL = minutes
DH = seconds
DL = 1, if daylight savings; 0 if standard time
Return: CMOS clock set
-----------------------------------------------------------
INT 1A - CLOCK - READ DATE FROM REAL TIME CLOCK (AT,XT286,CONV,PS)
AH = 04h
Return: DL = day
DH = month
CL = year
CH = century (19 or 20)
-----------------------------------------------------------
INT 1A - CLOCK - SET DATE IN REAL TIME CLOCK (AT,XT286,CONV,PS)
AH = 05h
DL = day
DH = month
CL = year
CH = century (19 or 20)
Return: CMOS clock set
-----------------------------------------------------------
INT 1A - CLOCK - SET ALARM (AT,XT286,CONV,PS)
AH = 06h
CH = hours
CL = minutes
DH = seconds
Return: CF set if alarm already set or clock inoperable
INT 4Ah will be called when alarm goes off
-----------------------------------------------------------
INT 1A - CLOCK - RESET ALARM (AT,XT286,CONV,PS)
AH = 07h
Return: alarm disabled
-----------------------------------------------------------
INT 1A - CLOCK - SET RTC ACTIVATED POWER ON MODE (CONVERTIBLE)
AH = 08h
CH = hours in BCD
CL = minutes in BCD
DH = seconds in BCD
-----------------------------------------------------------
INT 1A - CLOCK - READ RTC ALARM TIME AND STATUS (CONV,PS30)
AH = 09h
Return: CH = hours in BCD
CL = minutes in BCD
DH = seconds in BCD
DL = alarm status
0 alarm not enabled
1 alarm enabled but will not power up system
2 alarm will power up system
-----------------------------------------------------------
INT 1A - CLOCK - READ SYSTEM-TIMER DAY COUNTER (XT2,PS)
AH = 0Ah
???
Return: ???
-----------------------------------------------------------
INT 1A - CLOCK - SET SYSTEM-TIMER DAY COUNTER (XT2,PS)
AH = 0Bh
???
Return: ???
-----------------------------------------------------------
INT 1A - SET UP SOUND MULTIPLEXOR (PCjr ONLY)
AH = 80h
AL = 0 source is 8253 channel 2
1 source is cassette input
2 source is I/O channel "Audio IN"
3 source is sound generator chip
-----------------------------------------------------------
INT 1B - CTRL-BREAK KEY
This interrupt is called when the keyboard scanner of the IBM
machines detects CTRL and BREAK pressed at the same time. It
normally points to a short routine in DOS which sets the
Ctrl-C flag, thus invoking INT 23h the next time DOS checks
for Ctrl-C.
-----------------------------------------------------------
INT 1C - CLOCK TICK
This interrupt is called (in the IBM) at the end of each time-update
operation by the time-of-day routines. It normally points to an IRET.
-----------------------------------------------------------
INT 1D -> 6845 VIDEO INIT TABLES
table for modes 0 and 1 /
table for modes 2 and 3 / each table is 16 bytes long and
table for modes 4,5, and 6 / contains values for 6845 registers
table for mode 7 /
4 words -- size of video RAM for modes 0/1, 2/3, 4/5, and 6/7
8 bytes -- number of columns in each mode
8 bytes -- video controller mode byte for each mode
-----------------------------------------------------------
INT 1E -> DISKETTE PARAMS (BASE TABLE)
(Default at F000:EFC7 in PC and most compatibles)
DB step rate & head unload times
DB head load time & DMA
DB motor off time in clock ticks (36 or 37 typical)
DB sector size in bytes (0->128, 1->256, 2->512, 3->1024)
DB last sector number (8 or 9 typical)
DB inter-sector gap size on read/write (42 typical)
DB data transfer length (255 typical)
DB inter-sector gap size on format (80 typical)
DB sector fill on format (F6h typical)
DB head-settle time ms (typical 25, 1.10->0, 2.10->15, 3.10->1)
DB motor start-up time (1/8 secs) (typical 4, 2.10->2)
-----------------------------------------------------------
INT 1F -> GRAPHICS SET 2
(NOT a vector!) pointer to bitmaps for high 128 chars
-----------------------------------------------------------
INT 20 - Minix - SEND/RECEIVE MESSAGE
AX = process ID of other process
BX = pointer to message
CX = 1 send
2 receive
3 send&receive
Note: the message contains the system call number (numbered as in V7 Unix(tm))
and the call parameters
-----------------------------------------------------------
INT 20 - DOS - PROGRAM TERMINATION
returns to DOS--identical to INT 21/AH=00h
-----------------------------------------------------------
INT 21 - DOS - PROGRAM TERMINATION
AH = 00h
Return: never
-----------------------------------------------------------
INT 21 - DOS - KEYBOARD INPUT
AH = 01h
Return: AL = character read
Note: ^C/^Break are checked, and INT 23h executed if read
-----------------------------------------------------------
INT 21 - DOS - DISPLAY OUTPUT
AH = 02h
DL = character
-----------------------------------------------------------
INT 21 - DOS - AUX INPUT
AH = 03h
Return: AL = character read
-----------------------------------------------------------
INT 21 - DOS - AUX OUTPUT
AH = 04h
DL = character to send
-----------------------------------------------------------
INT 21 - DOS - PRINTER OUTPUT
AH = 05h
DL = character to print
-----------------------------------------------------------
INT 21 - DOS - DIRECT CONSOLE I/O CHARACTER OUTPUT
AH = 06h
DL = character <> FFh
-----------------------------------------------------------
INT 21 - DOS - DIRECT CONSOLE I/O CHARACTER INPUT
AH = 06h
DL = 0FFh
Return: ZF set = no character
ZF clear = character recieved
AL = character
Notes: Character is echoed to STDOUT if received.
^C/^Break are NOT checked
-----------------------------------------------------------
INT 21 - DOS - DIRECT STDIN INPUT, NO ECHO
AH = 07h
Note: same as function 06h for input but char not echoed
-----------------------------------------------------------
INT 21 - DOS - KEYBOARD INPUT, NO ECHO
AH = 08h
Return: AL = character
Note: same as function 07h, but ^C/^Break are checked
-----------------------------------------------------------
INT 21 - DOS - PRINT STRING
AH = 09h
DS:DX = address of string terminated by "$"
-----------------------------------------------------------
INT 21 - DOS - BUFFERED KEYBOARD INPUT
AH = 0Ah
DS:DX = address of buffer
Note: first byte of buffer must contain maximum length
on entry, second byte contains actual length of previous line which may
be recalled with the DOS line-editing commands
on return the second byte contains actual length, third and
subsequent bytes contain the input line
-----------------------------------------------------------
INT 21 - DOS - CHECK STANDARD INPUT STATUS
AH = 0Bh
Return: AL = FFh if character available
00h if no character
-----------------------------------------------------------
INT 21 - DOS - CLEAR KEYBOARD BUFFER
AH = 0Ch
AL must be 1, 6, 7, 8, or 0Ah.
Notes: Flushes all typeahead input, then executes function specified by AL
(effectively moving it to AH and repeating the INT 21 call).
If AL contains a value not in the list above, the keyboard buffer is
flushed and no other action is taken.
-----------------------------------------------------------
INT 21 - DOS - DISK RESET
AH = 0Dh
Note: Flushes all disk buffers.
-----------------------------------------------------------
INT 21 - DOS - SELECT DISK
AH = 0Eh
DL = new default drive number (0 = A, 1 = B, etc.)
Return: AL = number of logical drives
-----------------------------------------------------------
INT 21 - DOS - OPEN DISK FILE
AH = 0Fh
DS:DX = address of FCB
Return: AL = 00h file found
FFh file not found
-----------------------------------------------------------
INT 21 - DOS - CLOSE DISK FILE
AH = 10h
DS:DX = address of FCB
Return: AL = 00h directory update successful
FFh file not found in directory
-----------------------------------------------------------
INT 21 - DOS - SEARCH FIRST USING FCB
AH = 11h
DS:DX = address of FCB
Return: AL = status
00h file found
FFh file not found
Note: If file found, FCB is created at DTA address and set up to
OPEN or DELETE it.
-----------------------------------------------------------
INT 21 - DOS - SEARCH NEXT USING FCB
AH = 12h
DS:DX = address of FCB
Return: AL = status
00h file found
FFh file not found
Note: If file found, FCB is created at DTA address and set up to
OPEN or DELETE it.
-----------------------------------------------------------
INT 21 - DOS - DELETE FILE via FCB
AH = 13h
DS:DX = address of FCB
Return: AL = status
00h file found
FFh file not found
-----------------------------------------------------------
INT 21 - DOS - SEQUENTIAL DISK FILE READ
AH = 14h
DS:DX = address of FCB
Return: AL = status
0 successful read
1 end of file
2 data transfer area too small
3 partial record, EOF
-----------------------------------------------------------
INT 21 - DOS - SEQUENTIAL DISK RECORD WRITE
AH = 15h
DS:DX = address of FCB
Return: AL = status
0 successful write
1 disk full
2 data transfer area too small
-----------------------------------------------------------
INT 21 - DOS - CREATE A DISK FILE
AH = 16h
DS:DX = address of FCB
Return: AL = status
00h successful creation
FFh directory full
-----------------------------------------------------------
INT 21 - DOS - RENAME FILE via FCB
AH = 17h
DS:DX = address of FCB
FCB contains new name starting at byte 17h.
Return: AL = status
00h file found
FFh file not found
-----------------------------------------------------------
INT 21 - DOS Internal - UNUSED
AH = 18h
Return: AL = 0
-----------------------------------------------------------
INT 21 - DOS - GET DEFAULT DISK NUMBER
AH = 19h
Return: AL = current drive number (letter - 'A')
-----------------------------------------------------------
INT 21 - DOS - SET DISK TRANSFER AREA ADDRESS
AH = 1Ah
DS:DX = address of buffer
-----------------------------------------------------------
INT 21 - DOS - GET DEFAULT DRIVE DISK SIZE
AH = 1Bh
Return: DS:BX points to FAT ID byte
DX = number of allocation units on disk
AL = number of sectors per allocation unit (cluster)
CX = number of bytes per sector
-----------------------------------------------------------
INT 21 - DOS - GET SPECIFIC DRIVE'S DISK SIZE
AH = 1Ch
DL = Drive Number to check
Return: DS:BX points to FAT ID byte
DX = number of allocation units on disk
AL = number of sectors per allocation unit (cluster)
CX = number of bytes per sector
-----------------------------------------------------------
INT 21 - DOS Internal - UNUSED
AH = 1Dh
Return: AL = 0
-----------------------------------------------------------
INT 21 - DOS Internal - UNUSED
AH = 1Eh
Return: AL = 0
-----------------------------------------------------------
INT 21 - DOS Internal - GET DEFAULT DRIVE PARAMETER BLOCK
AH = 1Fh
Return: AL = 00h No Error
FFh Error
DS:BX = pointer to drive parameter block
Note: for DOS 2.x and 3.x, this just invokes function 32h with DL = 0
-----------------------------------------------------------
INT 21 - DOS Internal - UNUSED
AH = 20h
Return: AL = 0
-----------------------------------------------------------
INT 21 - DOS - RANDOM DISK RECORD READ
AH = 21h
DS:DX = address of FCB
Return: AL = status
0 successful read
1 end of file
2 data transfer area too small
3 partial record, EOF
-----------------------------------------------------------
INT 21 - DOS - RANDOM DISK RECORD WRITE
AH = 22h
DS:DX = address of FCB
Return: AL = status (see AH = 21h above)
-----------------------------------------------------------
INT 21 - DOS - GET FILE SIZE
AH = 23h
DS:DX = address of FCB
Return: AL = status
00h file found
FFh file not found
Note: FCB set to number of records
-----------------------------------------------------------
INT 21 - DOS - SET RANDOM RECORD FIELD
AH = 24h
DS:DX = address of FCB
Return: Random Record Field of FCB is set to be same as Current Block
and Current Record.
Note: FCB must be OPEN already
-----------------------------------------------------------
INT 21 - DOS - SET INTERRUPT VECTOR
AH = 25h
AL = interrupt number
DS:DX = new vector to be used for specified interrupt
-----------------------------------------------------------
INT 21 - DOS - CREATE PSP
AH = 26h
DX = Segment number to set up PSP at
Return: Current PSP is copied to specified segment
-----------------------------------------------------------
INT 21 - DOS - RANDOM BLOCK READ
AH = 27h
DS:DX = address of FCB
CX = number of records to be read
Return: AL = status
0 successful read
1 end of file
2 data transfer area too small
3 partial record, EOF
-----------------------------------------------------------
INT 21 - DOS - RANDOM BLOCK WRITE
AH = 28h
DS:DX = address of FCB
CX = number of records to be written
if zero, truncate file to current random file position
Return: AL = status
0 successful write
1 disk full
2 data transfer area too small
-----------------------------------------------------------
INT 21 - DOS - PARSE FILENAME
AH = 29h
DS:SI = pointer to string to parse
ES:DI = pointer to memory to fill with unopened FCB
AL = bit mask to control parsing
0 = 0: parsing stops if file separator found
1: leading separator ignored
1 = 0: drive number in FCB set to default drive if not present
in string
1: drive number in FCB not changed
2 = 0: filename in FCB set to blanks if no filename in string
1: filename in FCB not changed if string does not contain
a filename
3 = 0: extension in FCB set to blanks if no extension in string
1: extension left unchanged
Return: AL = 00: no wildcards in name or extension
01: wildcards appeared
DS:SI = pointer to first byte after parsed string
ES:DI = unopened FCB
-----------------------------------------------------------
INT 21 - DOS - GET CURRENT DATE
AH = 2Ah
Return: DL = day
DH = month
CX = year
AL = day of the week (0=Sunday, 1=Monday, etc.)
-----------------------------------------------------------
INT 21 - DOS - SET CURRENT DATE
AH = 2Bh
DL = day
DH = month
CX = year
Return: AL = 00h if no error
= FFh if bad value sent to routine
Note: DOS 3.3 also sets CMOS clock
-----------------------------------------------------------
INT 21 - DESQview - INSTALLATION CHECK
AH = 2Bh
AL = subfunction
01h get version
Return: BX = version (v2.00 returns 0002h, v2.01 returns 0201h)
02h get shadow buffer info, and start shadowing
Return: BH = rows in shadow buffer
BL = columns in shadow buffer
DX = segment of shadow buffer
04h get shadow buffer info
Return: BH = rows in shadow buffer
BL = columns in shadow buffer
DX = segment of shadow buffer
05h stop shadowing
CX = 4445h ('DE')
DX = 5351h ('SQ')
Return: AL = FFh if DESQview not installed
-----------------------------------------------------------
INT 21 - DOS - GET CURRENT TIME
AH = 2Ch
Return: CH = hours
CL = minutes
DH = seconds
DL = hundredths of seconds
Note: time is updated approximately every 5/100 second
-----------------------------------------------------------
INT 21 - DOS - SET CURRENT TIME
AH = 2Dh
CH = hours
CL = minutes
DH = seconds
DL = hundredths of seconds
Return: AL = 00h if no error
= FFh if bad value sent to routine
Note: DOS 3.3 also sets CMOS clock
-----------------------------------------------------------
INT 21 - DOS - SET VERIFY FLAG
AH = 2Eh
DL = 0
AL = 1 VERIFY on
0 VERIFY off
-----------------------------------------------------------
INT 21 - DOS 2+ - GET DISK TRANSFER AREA ADDRESS
AH = 2Fh
Return: ES:BX = address of DTA
-----------------------------------------------------------
INT 21 - DOS 2+ - GET DOS VERSION
AH = 30h
Return: AL = Major Version number
AH = Minor Version number
BH = OEM number
00h IBM
16h DEC
BL:CX = 24-bit user number
-----------------------------------------------------------
INT 21 - DOS 2+ - TERMINATE BUT STAY RESIDENT
AH = 31h
AL = exit code
DX = program size, in paragraphs
-----------------------------------------------------------
INT 21 - DOS Internal - GET DRIVE PARAMETER BLOCK
AH = 32h
DL = drive number
0 = default, 1 = A, etc.
Return: AL = 0FFh if invalid drive number, else
DS:BX = address of drive parameter block.
STRUCTURE OF DOS DRIVE PARAMETER BLOCK:
DPBLOCK STRUCT ;Offset
DISK_OFFSET DB ? ; 0 drive number (0 = A, etc.)
UNIT_OFFSET DB ? ; 1 unit number within device driver
SECTOR_SIZE DW ? ; 2 number of bytes per sector
MAX_CLUSTER DB ? ; 4 largest sector number in cluster
; add one for number of sectors/cluster
LOG2_SECTORS DB ? ; 5 log base two of the cluster size
RESERVED DW ? ; 6 number of reserved (boot) sectors
FAT_COUNT DB ? ; 8 number of copies of the FAT
ROOT_COUNT DW ? ; 9 number of root directory entries
DATA_START DW ? ; 11 first data sector on medium
MAX_NUMBER DW ? ; 13 largest possible cluster number
; subtract one for number of data clusters
FAT_SECTORS DB ? ; 15 number of sectors in one FAT copy
ROOT_START DW ? ; 16 first sector of root directory
DEVICE_ADDR DD ? ; 18 address of device driver for this drive
DESCRIPTOR DB ? ; 22 media descriptor byte for medium
VALID_BYTE DB ? ; 23 0FFh indicates block must be rebuilt
NEXT_BLOCK DD ? ; 24 address of next device block in list
; from this point on, DOS 3 differs from DOS 2:
IF DOS2
DIR_START DW ? ; 28 starting cluster of current directory
; zero indicates the root directory
PATH_NAME DB 64 DUP (?)
; 30 ASCIZ current directory path string
ELSE DOS3
; on my XT, this was always:
DW 0
DW 0FFFFh
ENDIF
DPBLOCK ENDS
-----------------------------------------------------------
INT 21 - DOS 2+ - EXTENDED CONTROL-BREAK CHECKING
AH = 33h
AL = subfunction
00h Get State
01h Set
DL = 0 for OFF or 1 for ON
02h internal, called by PRINT.COM (DOS 3.1)
Return: DL = current BREAK setting if AL = 00h
0 BREAK=OFF
1 BREAK=ON
AL = FFh if error
-----------------------------------------------------------
INT 21 - DOS Internal - RETURN CritSectFlag POINTER
AH = 34h
Return: ES:BX points to DOS "Critical Section Flag"
Notes:
When byte pointed to is zero, DOS is supposed to be safe to interrupt.
NOT RELIABLE according to Chris Dunford.
Examination of DOS 2.10 code in this area indicates that the byte
immediately FOLLOWING this "Critical Section Flag" must be 00 to permit the
PRINT.COM interrupt to be called.
For DOS 3.0 and 3.1 (except COMPAQ DOS 3.0), the byte BEFORE the "Critical
Section Flag" must be zero, and for COMPAQ DOS 3.0, the byte 01AAh before it
must be zero.
-----------------------------------------------------------
INT 21 - DOS 2+ - GET INTERRUPT VECTOR
AH = 35h
AL = interrupt number
Return: ES:BX = value of interrupt vector
-----------------------------------------------------------
INT 21 - DOS 2+ - GET DISK SPACE
AH = 36h
DL = drive code (0 = default, 1 = A, 2 = B, etc.)
Return: AX = number of sectors per cluster
or 0FFFFh if invalid drive
BX = number of available clusters
CX = bytes per sector
DX = total clusters
Note: multiply AX x CX x BX for free space on disk
multiply AX x CX x DX for total disk space
-----------------------------------------------------------
INT 21 - DOS Internal - SWITCHAR/AVAILDEV
AH = 37h
AL = subfunction
0 Read switch character (returns current character in DL)
1 Set switch character (specify new character in DL)
2 (DOS 2.x only) Read device availability (as set by function AL=3)
3 (DOS 2.x only) Set device availability, where:
DL = 0 means /DEV/ must preceed device names
DL <> 0 means /DEV/ need not preceed device names
Return: DL = Switch character (if AL=0 or 1)
Device availability flag (if AL=2 or 3)
AL=0FFh means the value in AL was not in the range 0-3.
-----------------------------------------------------------
INT 21 - DOS 2+ - GET COUNTRY-DEPENDENT INFORMATION
AH = 38h
--DOS 2.x--
AL = 0 get current-country info
DS:DX = segment:offset of buffer for returned info
Return: BX = country code
buffer at DS:DX filled as follows:
bytes 0-1 = date format 0 = USA mm dd yy
1 = Europe dd mm yy
2 = Japan yy mm dd
byte 2 = currency symbol
byte 3 = 00h
byte 4 = thousands separator char
byte 5 = 00h
byte 6 = decimal separator char
byte 7 = 00h
bytes 8-1Fh reserved
--DOS 3.x--
AL = 0 for current country
AL = 01h thru 0FEh for specific country with code <255
AL = 0FFh for specific country with code >= 255
BX = 16-bit country code
DS:DX = segment:offset of buffer for returned info
DX = 0FFFFh if setting country code, rather than getting info
Return: (if DX <> 0FFFFh)
BX = country code
DS:DX filled in:
bytes 0-1 = date format (see above)
bytes 2-6 = currency symbol string, ASCIZ
byte 7 = thousands seaprator char
byte 8 = 00h
byte 9 = decimal separator char
byte 0Ah = 00h
byte 0Bh = date separator char
byte 0Ch = 00h
byte 0Dh = time separator char
byte 0Eh = 00h
byte 0Fh = currency format
bit 1 = number of spaces between value and curr sym
bit 0 = 0 if currency symbol precedes value
1 if currency symbol follows value
byte 10h = number of digits after decimal in currency
byte 11h = time format
bit 0 = 0 if 12-hour clock
1 if 24-hour clock
bytes 12h-15h = address of case map routine (FAR CALL)
byte 16h = data-list separator char
byte 17h = 00h
bytes 18h-21h reserved
If error:
CF set
AX = error code
-----------------------------------------------------------
INT 21 - DOS 2+ - CREATE A SUBDIRECTORY (MKDIR)
AH = 39h
DS:DX = address of ASCIZ pathname
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - REMOVE A DIRECTORY ENTRY (RMDIR)
AH = 3Ah
DS:DX = address of ASCIZ pathname
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - CHANGE THE CURRENT DIRECTORY (CHDIR)
AH = 3Bh
DS:DX = address of ASCIZ directory name
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - CREATE A FILE WITH HANDLE (CREAT)
AH = 3Ch
CX = attributes for file
DS:DX = address of ASCIZ filename
Return: CF = 1 if error
AX = Error Code
CF = 0 successful
AX = file handle
-----------------------------------------------------------
INT 21 - DOS 2+ - OPEN DISK FILE WITH HANDLE
AH = 3Dh
AL = access code
0 = Read Only
1 = Write Only
2 = Read/Write
AL bits 7-3 = file-sharing modes (DOS 3.x)
bit 7 = inheritance flag, set for no inheritance
bits 4-6 = sharing mode
000 compatibility mode
001 exclusive (deny all)
010 write access denied (deny write)
011 read access denied (deny read)
100 full access permitted (deny none)
bit 3 = reserved, should be zero
DS:DX = address of ASCIZ filename
Return: CF = 1 if error
AX = Error Code
CF = 0 successful
AX = file handle
-----------------------------------------------------------
INT 21 - DOS 2+ - CLOSE A FILE WITH HANDLE
AH = 3Eh
BX = file handle
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - READ FROM FILE WITH HANDLE
AH = 3Fh
BX = file handle
CX = number of bytes to read
DS:DX = address of buffer
Return: CF = 1 if error
AX = Error Code
CF = 0 successful
AX = number of bytes read
-----------------------------------------------------------
INT 21 - DOS 2+ - WRITE TO FILE WITH HANDLE
AH = 40h
BX = file handle
CX = number of bytes to write
DS:DX = pointer to buffer
Return: CF = 1 if error
AX = Error Code
CF = 0 successful
AX = number of bytes written
Note: if CX is zero, no data is written, and the file is truncated or extended
to the current position
-----------------------------------------------------------
INT 21 - DOS 2+ - DELETE A FILE (UNLINK)
AH = 41h
DS:DX = pointer to ASCIZ name of file to delete
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - MOVE FILE READ/WRITE POINTER (LSEEK)
AH = 42h
AL = method value
0 = offset from beginning of file
1 = offset from present location
2 = offset from end of file
BX = file handle
CX:DX = offset in bytes
Return: CF = 1 if error
AX = Error Code
CF = 0 successful
DX:AX = new offset
-----------------------------------------------------------
INT 21 - DOS 2+ - GET/PUT FILE ATTRIBUTES (CHMOD)
AH = 43h
AL =
0 = get file attributes
1 = put file attributes
CX = file attribute bits
0 = read only
1 = hidden file
2 = system file
3 = volume label
4 = subdirectory
5 = written since backup
DS:DX = pointer to ASCIZ file name
Return: CF = 1 if error
AX = Error Code if any
CX = file attributes on get
-----------------------------------------------------------
INT 21 - DOS 2+ - IOCTL
AH = 44h
AL =
0 = Get device information (DX)
1 = Set device information (DH must be 0 on entry)
DX BITS =
0 = console input device
1 = console output device
2 = null device
3 = clock device
5 = binary mode
6 = EOF
7 = device is character device if set
if not, EOF = 0 if channel has been written
bits 0-5 are block device number
12 = network device
14 = can process control strings (AL=2-5, can only be read)
15 reserved
2 = Read CX bytes to DS:DX from BX control channel
Return: AX = number of bytes transferred
3 = Write CX bytes from DS:DX from BX control channel
Return: AX = number of bytes transferred
4 = as 2 but for drive BL
Return: AX = number of bytes transferred
5 = as 3 but for drive BL
Return: AX = number of bytes transferred
6 = Get input status
Return: AL = FFh for ready, 00h for not ready
7 = Get output status
Return: AL = FFh for ready or 00h for not ready
8 = Is block device BL changeable? (DOS 3.x)
Return: AX = 0 removable
1 fixed
9 = Is logical device BL local? (DOS 3.x)
DX (attribute word) bit 12 (1000h) = 0 = yes
10 = Is handle BX local? (DOS 3)
DX (attribute word) bit 15 (8000h) = 0 = yes
11 = Change sharing retry count to DX (def 3), (DOS 3.x)
delay CX (def 1)
12 = General IOCTL (DOS 3.3 [3.2?])
BX = file handle (or BL = drive number with 0 = default)
Return: CF = 1 if error
AX = Error Code
Note: only subfunctions 00h,06h,07h are available for files
-----------------------------------------------------------
INT 21 - DOS 2+ - CREATE DUPLICATE HANDLE (DUP)
AH = 45h
BX = file handle to duplicate
Return: CF = 1 if error
AX = Error Code
CF = 0 successful
AX = new file handle
-----------------------------------------------------------
INT 21 - DOS 2+ - FORCE DUPLICATE HANDLE (FORCDUP,DUP2)
AH = 46h
BX = Existing file handle
CX = new file handle
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - GET CURRENT DIRECTORY
AH = 47h
DL = drive (0=default, 1=A, etc.)
DS:SI points to 64-byte buffer area
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - ALLOCATE MEMORY
AH = 48h
BX = number of 16-byte paragraphs desired
Return: CF = 1 if error
AX = Error Code
BX = Maximum available
CF = 0 successful
AX = segment of allocated memory block
-----------------------------------------------------------
INT 21 - DOS 2+ - FREE MEMORY
AH = 49h
ES = Segment address of area to be freed
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - ADJUST MEMORY BLOCK SIZE (SETBLOCK)
AH = 4Ah
ES = Segment address of block to change
BX = New size in paragraphs
Return: CF = 1 if error
AX = Error Code
BX = Maximum size possible for the block
-----------------------------------------------------------
INT 21 - DOS 2+ - LOAD OR EXECUTE (EXEC)
AH = 4Bh
AL = subfunction
0 = load and execute program
2 = load (Internal) but do not execute
3 = load overlay; do not create PSP
DS:DX = filename
ES:BX = parameter block
AL =
0 => WORD segment environment pointer
DWORD command line pointer
DWORD FCB 1
DWORD FCB 2
3 => WORD segment load address
WORD segment relocation factor
Return: CF = 1 if error
AX = Error Code
struct exec { /* structure of .EXE file header */
unsigned exec_magic; /* 0x4d, 0x5a signature */
unsigned exec_isr; /* image size remainder (mod 512) */
unsigned exec_size; /* file size in pages (512) */
unsigned exec_nrel; /* number of relocation items */
unsigned exec_hsize; /* header size in paragraphs */
unsigned exec_min; /* minimum extra paragraphs */
unsigned exec_max; /* maximum extra paragraphs */
unsigned exec_ss; /* stack segment */
unsigned exec_sp; /* stack offset */
unsigned exec_cksum; /* word checksum of entire file */
unsigned exec_pc; /* initial pc */
unsigned exec_cs; /* code segment */
unsigned exec_orel; /* offset of relocation table */
unsigned exec_ovno; /* overlay number */
};
-----------------------------------------------------------
INT 21 - DOS 2+ - QUIT WITH EXIT CODE (EXIT)
AH = 4Ch
AL = exit code
Return: never returns
-----------------------------------------------------------
INT 21 - DOS 2+ - GET EXIT CODE OF SUBPROGRAM (WAIT)
AH = 4Dh
Return: AL = exit code of subprogram (functions 31h or 4Ch)
AH = circumstance which caused termination
0 = Terminate/abort
1 = Control-C
2 = Hard error
3 = Terminate and stay resident
-----------------------------------------------------------
INT 21 - DOS 2+ - FIND FIRST ASCIZ (FIND FIRST)
AH = 4Eh
CX = search attributes
DS:DX = pointer to ASCIZ filename
Return: CF = 1 if error
AX = Error Code if any
[DTA] = data block
byte 00h: drive letter (undocumented)
bytes 01h-0Bh: search template (undocumented)
bytes 0Ch-14h: reserved
byte 15h: attribute of file found
bytes 16h-17h: file time
bytes 18h-19h: file date
bytes 1Ah-1Dh: file size
bytes 1Eh-3Ah: ASCIZ filename+extension
-----------------------------------------------------------
INT 21 - DOS 2+ - FIND NEXT ASCIZ (FIND NEXT)
AH = 4Fh
Return: CF = 1 if error
AX = Error Code
[DTA] = data block, see AH = 4Eh above
-----------------------------------------------------------
INT 21 - DOS Internal - SET PSP SEGMENT
AH = 50h
BX = Segment address of new PSP
Note: under DOS 2.xx, this function cannot be invoked inside an INT 28h handler
without a prior call to function 5Dh
-----------------------------------------------------------
INT 21 - DOS Internal - GET PSP SEGMENT
AH = 51h
Return: BX = Current PSP Segment
struct psp {
char psp_int20[2]; /* 00h: exit */
unsigned psp_msize; /* 02h: memory size in paragraphs */
char psp_res0[1]; /* 04h: ??? (0) */
char psp_dos[5]; /* 05h: far call to dos */
int (*psp_term)(); /* 0ah: terminate address */
unsigned psp_tseg; /* 0ch: terminate segment */
int (*psp_break)(); /* 0eh: break address */
unsigned psp_bseg; /* 10h: break segment */
int (*psp_error)(); /* 12h: error address */
unsigned psp_eseg; /* 14h: error segment */
unsigned psp_ppsp; /* 16h: parent psp segment */
char psp_ofile[20]; /* 18h: open files, 0xff = unused */
unsigned psp_envp; /* 2ch: environment segment */
char far *psp_oldstack; /* 2eh: far ptr to processes SS:SP??? */
int psp_nfiles; /* 32h: max open files */
char *psp_aofile; /* 34h: ofile address */
unsigned psp_aoseg; /* 36h: ofile segment */
char psp_res3[24]; /* 38h: unused??? */
char psp_int21[3]; /* 50h: int 21, far return */
char psp_res4[2]; /* 53h: unused??? */
char psp_xfcb1[7]; /* 55h: FCB #1 extension */
char psp_fcb1[9]; /* 5ch: FCB #1 */
char psp_xfcb2[7]; /* 65h: FCB #2 extension */
char psp_fcb2[20]; /* 6ch: FCB #2 */
char psp_dma[128]; /* 80h: Command Tail */
};
Note: under DOS 2.xx, this function cannot be invoked inside an INT 28h handler
without a prior call to function 5Dh
-----------------------------------------------------------
INT 21 - DOS Internal - GET DISK LIST
AH = 52h
Return: ES:BX points to DOS list of lists
List of Lists:
Bytes Value
-2&-1 Segment of first memory control block
0-3 Pointer to first DOS disk block (see func 36h)
4-7 ??? Partially Unknown. Pointer to a device driver. Maybe first
resident driver?
8-B Pointer to CLOCK$ device driver, whether installable or
resident
C-F Pointer to actual CON: device driver, whether installable
or resident
-----DOS 2.x
10 Number of logical drives in system
11-12 Maximum bytes/block of any block device
13-16 ???
17 Beginning (not a pointer. The real beginning!) of NUL device
driver. This is the first device on DOS's linked list
of device drivers.
-----DOS 3.x
10-11 Maximum bytes/block of any block device (0200h)
12-15 ??? Pointer to current directory block?
16-19 Partially Undefined: Pointer to array of drive info:
51h bytes per drive, starting with A: ...
00-3F Current path as ASCIZ, starting with 'x:/'
40-43 ??? I see zeros always
44 ??? Flags? I see 40h, except for
entry after last valid entry = 00h
45-48 Pointer to DOS Disk Block for this drive
49-4A ??? Current track or block? -1 if never accessed.
4B-4E ??? I see -1 always
4F-52 ??? I see 2 always
1A-1D ??? Pointer to data area, maybe including cluster
allocation table?
1E-1F ??? I see zero always
20 Number of block devices.
21 Value of LASTDRIVE command in CONFIG.SYS (default 5)
22 Beginning (not a pointer. The real beginning!) of NUL device
driver. This is the first device on DOS's linked list
of device drivers.
-----------------------------------------------------------
INT 21 - DOS Internal - TRANSLATE BPB
AH = 53h
DS:SI points to BPB (Bios Parameter Block)
ES:BP points to area for DOS Disk Block
Translates BPB (Bios Parameter Block, see below) into a DOS Disk Block
(see function call 32h).
BPB
Bytes Value
0-1 Bytes/sector. Get from DDB bytes 2-3.
2 Sectors/cluster. Get from: (DDB byte 4) + 1
3-4 Reserved sectors. Get from: DDB bytes 6-7
5 Number of FATs. Get from: DDB byte 8
6-7 Number of root dir entries. Get from: DDB bytes 9-A
8-9 Total # of sectors. Get from:
((DDB bytes D-E) - 1) * (sectors per cluster (BPB byte 2))
+ (DDB Bytes B-C)
A Media descriptor byte. Get from: DDB byte 16
B-C Number of sectors/FAT. Get from: DDB byte F
-----------------------------------------------------------
INT 21 - DOS 2+ - GET VERIFY FLAG
AH = 54h
Return: AL = 0 if flag OFF
AL = 1 if flag ON
-----------------------------------------------------------
INT 21 - DOS Internal - CREATE PSP
AH = 55h
DX = Segment number to set up PSP at
Note: Like func 26h but creates "child" PSP rather than copying existing one.
-----------------------------------------------------------
INT 21 - DOS 2+ - RENAME A FILE
AH = 56h
DS:DX = pointer to ASCIZ old name
ES:DI = pointer to ASCIZ new name
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 2+ - GET/SET FILE'S DATE/TIME
AH = 57h
AL = function code
0 = get date and time
1 = set date and time
CX = time to be set
DX = date to be set
BX = file handle
Return: CF = 1 if error
AX = Error Code
CX = time of last write (if AL = 0)
DX = date of last write (if AL = 0)
-----------------------------------------------------------
INT 21 - DOS 3.x - GET/SET MEMORY ALLOCATION STRATEGY
AH = 58h
AL = function code
0 = get allocation strategy
1 = set allocation strategy
BL = strategy code
0 first fit (use first memory block large enough)
1 best fit (use smallest memory block large enough)
2 last fit (use high part of last usable memory block)
Return: CF = 1 error
AX = Error Code
CF = 0 successful
AX = strategy code
Note: the Set subfunction accepts any value in BL; 2 or greater means last fit.
the Get subfunction returns the last value set, so programs should check
whether the value is >= 2, not just equal to 2.
-----------------------------------------------------------
INT 21 - DOS 3.x - GET EXTENDED ERROR CODE
AH = 59h
BX = version code (0000 for DOS 3.0)
Return: AX = extended error code
BH = class of error
BL = suggested action code
CH = locus (where error occurred)
Error codes:
01 function number invalid
02 file not found
03 path not found
04 too many open files
05 access denied
06 invalid handle
07 memory control block destroyed
08 insufficient memory
09 memory block address invalid
0A environment invalid
0B format invalid
0C access code invalid
0D data invalid
0F invalid drive
10 attempted to remove current directory
11 not same device
12 no more files
13 disk write-protected
14 unknown unit
15 drive not ready
16 unknown command
17 data error (CRC)
18 bad request structure length
19 seek error
1A unknwon media type
1B sector not found
1C printer out of paper
1D write fault
1E read fault
1F general failure
20 sharing violation
21 lock violation
22 disk change invalid
23 FCB unavailable
24 sharing buffer overflow
25-31 reserved
32 Network request not supported (DOS 3.1 + MS Networks)
33 Remote computer not listening
34 Duplicate name on network
35 Network name not found
36 Network busy
37 Network device no longer exists
38 Network BIOS command limit exceeded
39 Network adapter hardware error
3A Incorrect response from network
3B Unexpected network error
3C Incompatible remote adapter
3D Print queue full
3E Queue not full
3F Not enough space to print file
40 Network name was deleted
41 Network: Access denied
42 Network device type incorrect
43 Network name not found
44 Network name limit exceeded
45 Network BIOS session limit exceeded
46 Temporarily paused
47 Network request not accepted
48 Print/disk redirection paused (DOS 3.1 + MS Networks)
49-4F reserved
50 file exists
51 reserved
52 cannot make directory
53 fail on INT 24h
Error Classes:
01 out of resource
02 temporary situation
03 authorization (denied access)
04 internal
05 hardware failure
06 system failure
07 application program error
08 not found
09 bad format
0A locked
0B media error
0C already exists
0D unknown
Suggested Action:
01 retry
02 delayed retry
03 prompt user
04 abort after cleanup
05 immediate abort
06 ignore
07 retry after user intervention
Error Locus:
01 unknown or not appropriate
02 block device
03 network related
04 serial device
05 memory related
-----------------------------------------------------------
INT 21 - DOS 3.x - CREATE TEMPORARY FILE
AH = 5Ah
DS:DX = pointer to ASCIZ directory path name
CX = file attribute
Return: CF = 1 if error
AX = Error Code if any
DS:DX = path name
Note: The file created is not truly "temporary". It MUST be removed by the
user.
-----------------------------------------------------------
INT 21 - DOS 3.x - CREATE NEW FILE
AH = 5Bh
DS:DX = pointer to ASCIZ directory path name
CX = file attribute
Return: CF = 1 if error
AX = Error Code if any
DS:DX = path name
Note: Unlike function 3Ch, function 5Bh will fail if the file already exists.
-----------------------------------------------------------
INT 21 - DOS 3.x - LOCK/UNLOCK FILE ACCESS
AH = 5Ch
AL = 0 if lock
1 if unlock
BX = file handle
CX:DX = starting offset of region to lock
SI:DI = size of region to lock
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 3.x Internal - GET ADDRESS OF CRITICAL ERROR FLAG
AX = 5D06h
Return: DS:SI = pointer to critical error flag
CX = ???
DX = ???
Note: this call also does a lot of other work in addition to returning the
pointer
Note: setting CritErr flag allows use of functions 50h/51h from INT 28h under
DOS 2.x by forcing use of correct stack
-----------------------------------------------------------
INT 21 - DOS 3.x Internal - ???
AH = 5Dh
AL = subfunction
07h: ???
08h: (used by COMMAND.COM)
09h: (used by COMMAND.COM)
-----------------------------------------------------------
INT 21 - DOS 3.1 + Microsoft Networks - GET MACHINE NAME
AX = 5E00h
DS:DX -> buffer for ASCIZ name
Return: CF = 1 if error
AX = Error Code
CH = 0 if name not defined
CL = NETBIOS name number
DS:DX -> pointer to identifier if CH <> 0
-----------------------------------------------------------
INT 21 - DOS 3.1 + Microsoft Networks - SET PRINTER SETUP
AX = 5E02h
BX = Redirection list index
CX = length of setup string <= 64
DS:SI -> string buffer
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 3.1 + Microsoft Networks - GET PRINTER SETUP
AX = 5E03h
BX = Redirection list index
ES:DI -> string buffer
Return: CF = 1 if error
AX = Error Code
CX = length of setup string <= 64
-----------------------------------------------------------
INT 21 - DOS 3.1 + Microsoft Networks - GET REDIRECTION LIST ENTRY
AX = 5F02h
BX = Redirection list index
DS:SI -> 16 char local device name buffer
ES:DI -> 128 char network name buffer
Return: CF = 1 if error
AX = Error Code
BH = Device status flag (BIT 0 = 0 if valid)
BL = device type (03 if printer, 04 if drive)
CX = stored parameter value
Note: DX and BP are destroyed by this call!
-----------------------------------------------------------
INT 21 - DOS 3.1 + Microsoft Networks - REDIRECT DEVICE
AX = 5F03h
BL = device type
03 = printer device
04 = file device
CX = stored parameter value
DS:SI -> source device name
ES:DI -> destination ASCIZ network path + ASCIZ password
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 3.1 + Microsoft Networks - CANCEL REDIRECTION
AX = 5F04h
DS:SI -> device name or network path
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 21 - DOS 3.x Internal - RESOLVE PATH STRING TO FULLY QUALIFIED PATH STRING
AH = 60h
DI:SI = relative path strings
ES:DI = buffer for fully qualified name
Return: buffer filled with qualified name; may return error code, unknown.
-----------------------------------------------------------
INT 21 - DOS 3.x Internal - UNUSED
AH = 61h
Return: AL = 0
-----------------------------------------------------------
INT 21 - DOS 3.x - GET PSP ADDRESS
AH = 62h
Return: BX = segment address of PSP
-----------------------------------------------------------
INT 21 - DOS 2.25 only - GET LEAD BYTE TABLE
AH = 63h
AL = subfunction
0 = get system lead byte table
1 = set/clear interim console flag
DL = 1/0 to set/clear interim console flag
2 = get interim console flag
Return: DS:SI -> lead byte table (AL = 0)
DL = interim console flag (AL = 2)
-----------------------------------------------------------
INT 21 - DOS 3.3 Internal - ???
AH = 64h
-----------------------------------------------------------
INT 21 - DOS 3.3 - GET EXTENDED COUNTRY INFORMATION
AH = 65h
AL = info ID (1 - 6)
BX = code page (-1=global code page)
DX = country ID (-1=current country)
ES:DI = pointer to country information buffer
CX = size of buffer
Return: AX = error code if carry set, otherwise
CX = size of country information returned
ES:DI = pointer to country information:
1 BYTE info ID
if info ID <> 1
1 DWORD pointer to information
if info ID == 1
1 WORD size
1 WORD country ID
1 WORD code page
34 BYTE see function 38h
-----------------------------------------------------------
INT 21 - DOS 3.3 - GET/SET GLOBAL CODE PAGE TABLE
AH = 66h
AL = 00h get global code page
Return: AX = error code if carry flag set
BX = active code page
DX = system code page
= 01h set global page
BX = active code page
437 US
860 Portugal
863 Canada (French)
865 Norway/Denmark
DX = system code page (active page at boot time)
Return: AX = error code if carry flag set
-----------------------------------------------------------
INT 21 - DOS 3.3 - SET HANDLE COUNT
AH = 67h
BX = desired number of handles (max 255)
Return: Carry clear if ok
Carry set if error (and error code in AX)
-----------------------------------------------------------
INT 21 - DOS 3.3 - COMMIT FILE, WRITE ALL BUFFERED DATA TO DISK
AH = 68h
BX = file handle
Return: carry flag set on error (and error code in AX)
-----------------------------------------------------------
INT 21 - DoubleDos - INSTALLATION CHECK
AX = E400h
Return: AL <> 0 if DoubleDos is active
-----------------------------------------------------------
INT 21 - DoubleDos - TURN OFF TASK SWITCHING
AH = EAh
Return: task switching turned off
-----------------------------------------------------------
INT 21 - DoubleDos - TURN ON TASK SWITCHING
AH = EBh
Return: task switching turned on
-----------------------------------------------------------
INT 21 - DoubleDos - GET VIRTUAL SCREEN ADDRESS
AH = ECh
Return: ES = segment of virtual screen
Note: Screen address can change if task-switching is on!!
-----------------------------------------------------------
INT 21 - DoubleDos - GIVE AWAY TIME TO OTHER TASKS
AH = EEh
AL = number of 55ms time slices to give away
Return: returns after giving away time slices
-----------------------------------------------------------
INT 21 - CED - INSTALLABLE COMMANDS
AH = FFh
AL = 0 add installable command
BL = mode - bit 0 = 1 callable from DOS prompt
bit 1 = 1 callable from application
DS:SI pointer to CR-terminated command name
ES:DI pointer to FAR routine entry point
AL = 1 remove installable command
DS:SI pointer to CR-terminated command name
AL = 2 reserved, may be used to test for CED installation
Return: CF set on error
AX = 01h invalid function
02h command not found (subfunction 1 only)
08h insufficient memory (subfunction 0 only)
0Eh bad data (subfunction 0 only)
AH = 0FFh if CED not installed
-----------------------------------------------------------
INT 22 - DOS - TERMINATE ADDRESS
FAR (DWORD) address of routine to be executed when program "returns to DOS".
Should NEVER be called directly.
-----------------------------------------------------------
INT 23 - DOS - CONTROL "C" EXIT ADDRESS
Automatically called from keyboard scanner when CTRL-C or CTRL-BREAK is
detected. Normally aborts program and returns to DOS, but may be changed.
-----------------------------------------------------------
INT 24 - DOS - FATAL ERROR HANDLER ADDRESS
Automatically called upon detection of unrecoverable I/O error.
Normally points to routine in resident part of COMMAND.COM that prints
"Abort, Retry, Ignore?" message and takes the reply, but may be overridden
if desired.
Provides the following values in registers on entry to interrupt handler:
AH: bit 7 = 0 disk I/O error
= 1 other error -- if block device, bad FAT
-- if char device, code in DI
bit 6 unused
bit 5 = 1 if Ignore allowed, 0 if not (DOS 3.2 ???)
bit 4 = 1 if Retry allowed, 0 if not (DOS 3.2 ???)
bit 3 = 1 if Fail allowed, 0 if not (DOS 3.2+)
bit 2 / disk area of error 00 = DOS area 01 = FAT
bit 1 / 10 = root dir 11 = data area
bit 0 = 1 if write, 0 if read
AL = drive number if AH bit 7 = 1, otherwise undefined
BP:SI = address of device header for which error occurred
block device if high bit of BP:SI+4 = 1
low byte of DI:
00h write-protect error
01h unknown unit
02h drive not ready
03h unknown command
04h data error (bad CRC)
05h bad request structure length
06h seek error
07h unknown media type
08h sector not found
09h printer out of paper
0Ah write fault
0Bh read fault
0Ch general failure
0Dh (DOS 3.x) sharing violation
0Eh (DOS 3.x) lock violation
0Fh (DOS 3.x) invalid disk change
10h (DOS 3.x) FCB unavailable
11h (DOS 3.x) sharing buffer overflow
Handler must return
AL = 00 ignore error
= 01 retry operation
= 02 terminate program through INT 22h
= 03 fail system call in progress (DOS 3.2+)
-----------------------------------------------------------
INT 25 - DOS - ABSOLUTE DISK READ (except COMPAQ DOS 3.31 >32M partition)
AL = Drive number (0=A, 1=B, etc)
DS:BX = Disk Transfer Address (buffer)
CX = Number of sectors to read
DX = First relative sector to read
Return: CF = 1 if error
AL = error code issued to INT 24h in low half of DI
AH = 80h if attachment failed to respond
40h if seek operation failed
20h if controller failed
10h if data error (bad CRC)
08h if DMA failure
04h if requested sector not found
03h if write-protected disk
02h if bad address mark
01h if bad command
Note: ORIGINAL FLAGS ON STACK!
-----------------------------------------------------------
INT 25 - COMPAQ DOS 3.31 - ABSOLUTE DISK READ (>32M hard-disk partition)
AL = Drive number (0=A, 1=B, etc)
CX = FFFFh
DS:BX = Packet address
DWORD sector number
WORD number of sectors to read
DWORD transfer address
Return: same as above???
Note: partition is potentially >32M (and requires this form of the call) if
bit 1 of device attribute word in device driver is set
-----------------------------------------------------------
INT 26 - DOS - ABSOLUTE DISK WRITE (except COMPAQ DOS 3.31 >32M partition)
AL = Drive number (0=A, 1=B, etc)
DS:BX = Disk Transfer Address (buffer)
CX = Number of sectors to write
DX = First relative sector to write
Return: CF = 1 if error
AL = error code issued to INT 24h in low half of DI
AH = same error codes as for INT 25h
Note: ORIGINAL FLAGS ON STACK!
-----------------------------------------------------------
INT 26 - COMPAQ DOS 3.31 - ABSOLUTE DISK WRITE (>32M hard-disk partition)
AL = Drive number (0=A, 1=B, etc)
CX = FFFFh
DS:BX = Packet address
DWORD sector number
WORD number of sectors to write
DWORD transfer address
Return: same as above???
Note: partition is potentially >32M (and requires this form of the call) if
bit 1 of device attribute word in device driver is set
-----------------------------------------------------------
INT 27 - DOS - TERMINATE BUT STAY RESIDENT
CS = current program segment
DX = last program byte + 1
Return: never
-----------------------------------------------------------
INT 28 - DOS Internal - KEYBOARD BUSY LOOP
This interrupt is called from inside the "get input from keyboard" routine
in DOS, if and only if it is safe to use INT 21 to access the disk at that
time. It is used primarily by the PRINT.COM routines and TSR programs, but
any number of other routines could be chained to it by saving the original
vector, and calling it with a FAR call (or just JMPing to it) at the end of
the new routine.
The INT 28h handler may invoke any INT 21h function except functions 00h
through 0Ch (and 50h/51h under DOS 2.xx unless DOS CritErr flag is set).
Until some program installs its own routine, this interrupt vector simply
points to an IRET opcode.
-----------------------------------------------------------
INT 29 - DOS Internal - FAST PUTCHAR
This interrupt is called from the DOS output routines if output is going to
a device rather than a file, and the device driver's attribute word has
bit 3 (04h) set to "1".
-----------------------------------------------------------
INT 2A - Microsoft Networks - NETWORK INSTALLATION CHECK
AH = 00h
Return: AH <> 0 if installed
-----------------------------------------------------------
INT 2A - Microsoft Networks - CHECK DIRECT I/O
AX = 0300h
DS:SI -> ASCIZ disk device name
Return: CF == 0 if allowed
-----------------------------------------------------------
INT 2A - Microsoft Networks - EXECUTE NETBIOS
AH = 04h
AL = 0 for error retry, 1 for no retry
ES:BX -> NCB
Return: AX = 0 for no error
AH = 1, AL = error code
-----------------------------------------------------------
INT 2A - Microsoft Networks - GET NETWORK RESOURCE INFORMATION
AX = 0500h
Return: AX = reserved
BX = number of network names
CX = number of commands
DX = number of sessions
-----------------------------------------------------------
INT 2A - NETBIOS 1.10 - NETWORK PRINT-STREAM CONTROL
AH = 06h
???
Return: ???
-----------------------------------------------------------
INT 2A - ???
AH = 20h
AL = 01h
???
Return: ???
Note: intercepted by DESQview 2.0
-----------------------------------------------------------
INT 2A - Microsoft Networks? - ???
AH = 82h
Return: ???
Note: Called by the INT 21h function dispatcher in DOS 3.10
-----------------------------------------------------------
INT 2B - Internal routine for MSDOS (IRET)
-----------------------------------------------------------
INT 2C - Internal routine for MSDOS (IRET)
-----------------------------------------------------------
INT 2D - Internal routine for MSDOS (IRET)
-----------------------------------------------------------
INT 2E - DOS Internal - EXECUTE COMMAND
DS:SI -> counted CR-terminated command string
The top-level command.com executes the command; all registers are destroyed
as in EXEC.
-----------------------------------------------------------
INT 2F notes
AH identifies which program is to handle the interrupt
00-7F reserved for DOS
C0-FF reserved for applications
AL is the function code
-----------------------------------------------------------
INT 2F - Multiplexor - PRINT - INSTALLATION CHECK
AX = 0100h
Return: AL =
FFh installed
01h not installed, not OK to install
00h not installed, OK to install
-----------------------------------------------------------
INT 2F - Multiplexor - PRINT - SUBMIT FILE
AX = 0101h
DS:DX -> packet of one byte level and DWORD file pointer
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 2F - Multiplexor - PRINT - REMOVE FILE
AX = 0102h
DS:DX -> file name (wildcards allowed)
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 2F - Multiplexor - PRINT - REMOVE ALL FILES
AX = 0103h
Return: CF = 1 if error
AX = Error Code
-----------------------------------------------------------
INT 2F - Multiplexor - PRINT - HOLD QUEUE/GET STATUS
AX = 0104h
Return: CF = 1 if error
AX = Error Code
01h function invalid
02h file not found
03h path not found
04h too many open files
05h access denied
08h queue full
09h spooler busy
0Ch name too long
0Fh drive invalid
DX = Error count
DS:SI -> print queue (null-string terminated
list of 64-byte ASCIZ file names)
-----------------------------------------------------------
INT 2F - Multiplexor - PRINT - RESTART QUEUE
AX = 0105h
Return: Flag CF = 1 if error
AX = Error Code if any
-----------------------------------------------------------
INT 2F - Multiplexor - ASSIGN - INSTALLATION CHECK
AX = 0600h
Return: AH <> 0 if installed
-----------------------------------------------------------
INT 2F - Multiplexor - ASSIGN - ???
AX = 0601h
???
Return: ???
-----------------------------------------------------------
INT 2F - Multiplexor - SHARE - ???
AH = 10h
AL = ???
Return: ???
-----------------------------------------------------------
INT 2F - Multiplexor - MSDOS Internal - ???
AH = 10h
AL =
0 returns immediately
nonzero sets flag in DOS, returns AX=0001 and CF=1
Note: this is without SHARE loaded, SHARE takes over this call
-----------------------------------------------------------
INT 2F - Multiplexor - MSDOS Internal - ???
AH = 11h
AL =
0 returns immediately
nonzero sets flag in DOS, returns AX=0001 and CF=1
Note: identical to AH=10h in PC-DOS 3.10 without SHARE loaded
-----------------------------------------------------------
INT 2F - Multiplexor - MSDOS Internal - ???
AH = 12h
???
Note: also reads value of word on top of stack immediately before invocation
-----------------------------------------------------------
INT 2F - Multiplexor - APPEND - INSTALLATION CHECK
AX = B700h
Return: AH <> 0 if installed
-----------------------------------------------------------
INT 2F - Multiplexor - APPEND - ???
AX = B701h
???
-----------------------------------------------------------
INT 2F - Multiplexor - APPEND - VERSION CHECK
AX = B702h
???
-----------------------------------------------------------
INT 2F - Multiplexor - Network - INSTALLATION CHECK
AX = B800h
Return: AH <> 0 if installed
-----------------------------------------------------------
INT 2F - Multiplexor - Network - GET CURRENT POST ADDRESS
AX = B803h
Return: ES:BX = post address
-----------------------------------------------------------
INT 2F - Multiplexor - Network - SET NEW POST ADDRESS
AX = B804h
ES:BX = new post address
-----------------------------------------------------------
INT 2F - Multiplexor - Network - VERSION CHECK
AX = B809h
???
-----------------------------------------------------------
INT 30 -> (NOT A VECTOR!) FAR JuMP instruction for CP/M-style calls
INT 31
-----------------------------------------------------------
INT 32 -> not used
-----------------------------------------------------------
INT 33 - MS MOUSE - RESET DRIVER AND READ STATUS
AX = 0000h
Return: AX = status
0 hardware/driver not installed
-1 hardware/driver installed
BX = number of buttons
-1 two buttons
0 other than two
-----------------------------------------------------------
INT 33 - MS MOUSE - SHOW MOUSE CURSOR
AX = 0001h
-----------------------------------------------------------
INT 33 - MS MOUSE - HIDE MOUSE CURSOR
AX = 0002h
Note: multiple calls to hide the cursor will require multiple calls to
function 01h to unhide it.
-----------------------------------------------------------
INT 33 - MS MOUSE - RETURN POSITION AND BUTTON STATUS
AX = 0003h
Return: BX = button status
bit 0 left button pressed if 1
bit 1 right button pressed if 1
CX = column
DX = row
-----------------------------------------------------------
INT 33 - MS MOUSE - POSITION MOUSE CURSOR
AX = 0004h
CX = column
DX = row
-----------------------------------------------------------
INT 33 - MS MOUSE - RETURN BUTTON PRESS DATA
AX = 0005h
BX = button
0 left
1 right
Return: AX = button states
bit 0 left button pressed if 1
bit 1 right button pressed if 1
BX = number of times specified button has been pressed since last call
CX = column at time specified button was last pressed
DX = row at time specified button was last pressed
-----------------------------------------------------------
INT 33 - MS MOUSE - RETURN BUTTON RELEASE DATA
AX = 0006h
BX = button
0 left
1 right
Return: AX = button states
bit 0 left button pressed if 1
bit 1 right button pressed if 1
BX = number of times specified button has been released since last call
CX = column at time specified button was last released
DX = row at time specified button was last released
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE HORIZONTAL CURSOR RANGE
AX = 0007h
CX = minimum column
DX = maximum column
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE VERTICAL CURSOR RANGE
AX = 0008h
CX = minimum row
DX = maximum row
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE GRAPHICS CURSOR
AX = 0009h
BX = column of cursor hot spot in bitmap
CX = row of cursor hot spot
ES:DX = pointer to bitmap
16 words, each defining the sixteen pixels of a row
low bit of each word is rightmost in row
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE TEXT CURSOR
AX = 000Ah
BX = hardware/software text cursor
0 software
CX = screen mask
DX = cursor mask
1 hardware
CX = start scan line
DX = end scan line
Note: when the software cursor is selected, the char/attribute data at the
current screen position is ANDed with the screen mask and then XORed
with the cursor mask
-----------------------------------------------------------
INT 33 - MS MOUSE - READ MOTION COUNTERS
AX = 000Bh
Return: CX = number of mickeys mouse moved horizontally since last call
DX = number of mickeys mouse moved vertically
Notes: a mickey is the smallest increment the mouse can sense
positive values indicate up/right
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE INTERRUPT SUBROUTINE PARAMETERS
AX = 000Ch
CX = call mask
bit 0 call if mouse moves
bit 1 call if left button pressed
bit 2 call if left button released
bit 3 call if right button pressed
bit 4 call if right button released
ES:DX = address of FAR routine
Note: when the subroutine is called, it is passed the following values:
AX = condition mask (same bit assignments as call mask)
BX = button state
CX = cursor column
DX = cursor row
DI = horizontal mickey count
SI = vertical mickey count
-----------------------------------------------------------
INT 33 - MS MOUSE - LIGHT PEN EMULATION ON
AX = 000Dh
-----------------------------------------------------------
INT 33 - MS MOUSE - LIGHT PEN EMULATION OFF
AX = 000Eh
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE MICKEY/PIXEL RATIO
AX = 000Fh
CX = number of mickeys per 8 pixels horizontally
DX = number of mickeys per 8 pixels vertically
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE SCREEN REGION FOR UPDATING
AX = 0010h
???
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE DOUBLE-SPEED THRESHOLD
AX = 0013h
???
-----------------------------------------------------------
INT 33 - MS MOUSE - EXCHANGE INTERRUPT SUBROUTINES
AX = 0014h
???
-----------------------------------------------------------
INT 33 - MS MOUSE - RETURN DRIVER STORAGE REQUIREMENTS
AX = 0015h
Return: BX = size of buffer needed to store driver state
-----------------------------------------------------------
INT 33 - MS MOUSE - SAVE DRIVER STATE
AX = 0016h
ES:DX = pointer to buffer
-----------------------------------------------------------
INT 33 - MS MOUSE - RESTORE DRIVER STATE
AX = 0017h
ES:DX = pointer to buffer containing saved state
-----------------------------------------------------------
INT 33 - MS MOUSE - DEFINE DISPLAY PAGE NUMBER
AX = 001Dh
???
-----------------------------------------------------------
INT 33 - MS MOUSE - RETURN DISPLAY PAGE NUMBER
AX = 001Eh
Return: ???
-----------------------------------------------------------
INT 34 - Turbo C/Microsoft languages - Floating Point emulation
-----------------------------------------------------------
INT 35 - Turbo C/Microsoft languages - Floating Point emulation
This interrupt emulates opcode D9h
-----------------------------------------------------------
INT 36 - Turbo C/Microsoft languages - Floating Point emulation
-----------------------------------------------------------
INT 37 - Turbo C/Microsoft languages - Floating Point emulation
This interrupt emulates opcode DBh
-----------------------------------------------------------
INT 38 - Turbo C/Microsoft languages - Floating Point emulation
-----------------------------------------------------------
INT 39 - Turbo C/Microsoft languages - Floating Point emulation
This interrupt emulates opcode DDh
-----------------------------------------------------------
INT 3A - Turbo C/Microsoft languages - Floating Point emulation
This interrupt emulates opcode DEh
-----------------------------------------------------------
INT 3B - Turbo C/Microsoft languages - Floating Point emulation
-----------------------------------------------------------
INT 3C - Turbo C/Microsoft languages - Floating Point emulation
This interrupt emulates instructions with an ES segment override
-----------------------------------------------------------
INT 3D - Turbo C/Microsoft languages - Floating Point emulation
This interrupt emulates a standalone FWAIT instruction
-----------------------------------------------------------
INT 3E - Turbo C/Microsoft languages - Floating Point emulation
-----------------------------------------------------------
INT 3F - Overlay manager interrupt (Microsoft LINK.EXE)
-----------------------------------------------------------
INT 40 -> Relocated (by fixed disk) Floppy Handler (original INT 13h)
-----------------------------------------------------------
INT 41 -> FIXED DISK PARAMETERS (XT,AT,XT2,XT286,PS except ESDI disks)
dw cylinders
db heads
dw 0
dw write pre-comp
db 0
db 0 "control byte"
db 0, 0, 0
dw landing zone
db sectors/track
db 0
-----------------------------------------------------------
INT 42 -> Relocated (by EGA) Video Handler (original INT 10h) (EGA,VGA,PS)
-----------------------------------------------------------
INT 43 -> EGA Initialization Params (EGA,VGA,PS)
-----------------------------------------------------------
INT 44 -> EGA/PCjr fonts (EGA,VGA,CONV,PS)
-----------------------------------------------------------
INT 45 -> reserved
-----------------------------------------------------------
INT 46 -> Secondary Fixed Disk Params (see INT 41h) (AT,XT286,PS except ESDI)
-----------------------------------------------------------
INT 47 -> reserved
-----------------------------------------------------------
INT 48 -> PCjr Cordless Keyboard Translation
-----------------------------------------------------------
INT 49 -> PCjr Non-keyboard Scan Code Translation Table
-----------------------------------------------------------
INT 4A -> AT User Alarm (AT,CONV,PS)
-----------------------------------------------------------
INT 4B -> reserved
-----------------------------------------------------------
INT 4C -> reserved
-----------------------------------------------------------
INT 4D -> reserved
-----------------------------------------------------------
INT 4E -> reserved
-----------------------------------------------------------
INT 4F -> reserved
-----------------------------------------------------------
INT 50-57 -> IRQ0-IRQ7 relocated by DESQview
-----------------------------------------------------------
INT 58 -> reserved
-----------------------------------------------------------
INT 59 - GSS Computer Graphics Interface (GSS*CGI)
DS:DX = Pointer to block of 5 array pointers
Return: CF = 0
AX = return code
CF = 1
AX = error code
Note: INT 59 is the means by which GSS*CGI language bindings communicate with
GSS*CGI device drivers and the GSS*CGI device driver controller. also
used by the IBM Graphic Development Toolkit
-----------------------------------------------------------
INT 5A - Cluster adapter BIOS entry address
???
-----------------------------------------------------------
INT 5B -> reserved
-----------------------------------------------------------
INT 5C - NETBIOS INTERFACE
ES:BX -> pointer to Network Control Block
Return: AL = Error Code (0 if none)
struct ncb {
unsigned char ncb_command;
unsigned char ncb_retcode;
unsigned char ncb_lsn;
unsigned char ncb_num;
char far *ncb_buffer;
unsigned short ncb_length;
char ncb_callname[16];
char ncb_name[16];
unsigned char ncb_rto;
unsigned char ncb_sto;
int (far *ncb_post)();
unsigned char ncb_lana_num;
unsigned char ncb_cmd_cplt;
char ncb_reserve[14];
};
Command codes:
#define NCB_NOWAIT 0x80
#define NCB_RESET 0x32
#define NCB_CANCEL 0x35
#define NCB_ADAPTER_STATUS 0x33
#define NCB_UNLINK 0x70
#define NCB_ADD_NAME 0x30
#define NCB_ADD_GROUP_NAME 0x36
#define NCB_DELETE_NAME 0x31
#define NCB_CALL 0x10
#define NCB_LISTEN 0x11
#define NCB_HANG_UP 0x12
#define NCB_SEND 0x14
#define NCB_CHAIN_SEND 0x17
#define NCB_RECEIVE 0x15
#define NCB_RECEIVE_ANY 0x16
#define NCB_SESSION_STATUS 0x34
#define NCB_SEND_DATAGRAM 0x20
#define NCB_SEND_BROADCAST_DATAGRAM 0x22
#define NCB_RECEIVE_DATAGRAM 0x21
#define NCB_RECEIVE_BROADCAST_DATAGRAM 0x23
struct name {
char nm_name[16];
unsigned char nm_num;
unsigned char nm_status;
};
struct astatus {
unsigned char as_id[6];
unsigned char as_jumpers;
unsigned char as_post;
unsigned char as_major;
unsigned char as_minor;
unsigned short as_interval
unsigned short as_crcerr;
unsigned short as_algerr;
unsigned short as_colerr;
unsigned short as_abterr;
unsigned long as_tcount;
unsigned long as_rcount;
unsigned short as_retran;
unsigned short as_xresrc;
char as_res0[8];
unsigned short as_ncbfree;
unsigned short as_ncbmax;
unsigned short as_ncbx;
char as_res1[4];
unsigned short as_sespend;
unsigned short as_msp;
unsigned short as_sesmax;
unsigned short as_bufsize;
unsigned short as_names;
struct name as_name[16];
};
Note: Sytek PCnet card uses DMA 3.
-----------------------------------------------------------
INT 5C - TOPS INTERFACE
ES:BX -> Network Control Block
Note: TOPS card uses DMA 1, 3 or none.
-----------------------------------------------------------
INT 5D -> reserved
-----------------------------------------------------------
INT 5E -> reserved
-----------------------------------------------------------
INT 5F -> reserved
-----------------------------------------------------------
INT 60 -> reserved for user interrupt
-----------------------------------------------------------
INT 61 -> reserved for user interrupt
-----------------------------------------------------------
INT 62 -> reserved for user interrupt
-----------------------------------------------------------
INT 63 -> reserved for user interrupt
-----------------------------------------------------------
INT 64 -> reserved for user interrupt
-----------------------------------------------------------
INT 65 -> reserved for user interrupt
-----------------------------------------------------------
INT 66 -> reserved for user interrupt
-----------------------------------------------------------
INT 67 - LIM EMS - GET MANAGER STATUS
AH = 40h
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
84h undefined function requested by application
Note: this call can be used only after establishing that the EMS driver
is in fact present
-----------------------------------------------------------
INT 67 - LIM EMS - GET PAGE FRAME SEGMENT
AH = 41h
Return: AH = 00h function successful
BX = segment of page frame
AH = error code (see AH=40h above)
-----------------------------------------------------------
INT 67 - LIM EMS - GET NUMBER OF PAGES
AH = 42h
Return: AH = 00h function successful
BX = number of unallocated pages
DX = total number of pages
AH = error code (see AH=40h above)
-----------------------------------------------------------
INT 67 - LIM EMS - GET HANDLE AND ALLOCATE MEMORY
AH = 43h
BX = number of logical pages to allocate
Return: AH = status
00h function successful
DX = handle
80h internal error
81h hardware malfunction
84h undefined function requested
85h no more handles available
87h more pages requested than physically exist
88h more pages requested than currently available
89h zero pages requested
-----------------------------------------------------------
INT 67 - LIM EMS - MAP MEMORY
AH = 44h
AL = physical page number (0-3)
BX = logical page number
DX = handle
Return: AH = status
00h function successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
8Ah invalid logical page number
8Bh illegal physical-page number
-----------------------------------------------------------
INT 67 - LIM EMS - RELEASE HANDLE AND MEMORY
AH = 45h
DX = EMM handle
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
86h error in save or restore of mapping context
-----------------------------------------------------------
INT 67 - LIM EMS - GET EMM VERSION
AH = 46h
Return: AH = status
00h successful
AL = EMM version number
80h internal error
81h hardware malfunction
84h undefined function requested
-----------------------------------------------------------
INT 67 - LIM EMS - SAVE MAPPING CONTEXT
AH = 47h
DX = handle
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
8Ch page-mapping hardware state save area is full
8Dh save of mapping context failed
-----------------------------------------------------------
INT 67 - LIM EMS - RESTORE MAPPING CONTEXT
AH = 48h
DX = handle
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
8Eh restore of mapping context failed
-----------------------------------------------------------
INT 67 - LIM EMS - reserved
AH = 49h
Note: defined in EMS 3.0, but undocumented in EMS 3.2
-----------------------------------------------------------
INT 67 - LIM EMS - reserved
AH = 4Ah
Note: defined in EMS 3.0, but undocumented in EMS 3.2
-----------------------------------------------------------
INT 67 - LIM EMS - GET NUMBER OF EMM HANDLES
AH = 4Bh
Return: AH = status
00h successful
BX = number of EMM handles
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
-----------------------------------------------------------
INT 67 - LIM EMS - GET PAGES OWNED BY HANDLE
AH = 4Ch
DX = EMM handle
Return: AH = status
00h successful
BX = number of logical pages
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
-----------------------------------------------------------
INT 67 - LIM EMS - GET PAGES FOR ALL HANDLES
AH = 4Dh
ES:DI = pointer to array to receive information
Return: AH = status
00h successful
BX = number of active EMM handles
array filled with 2-word entries, consisting of a handle
and the number of pages allocated to that handle
80h internal error
81h hardware malfunction
84h undefined function requested
-----------------------------------------------------------
INT 67 - LIM EMS - GET OR SET PAGE MAP
AH = 4Eh
AL = 00h if getting mapping registers
01h if setting mapping registers
02h if getting and setting mapping registers at once
03h if getting size of page-mapping array
DS:SI = pointer to array holding information (AL=01/02)
ES:DI = pointer to array to receive information (AL=00/02)
Return: AH = status
00h successful
AL = bytes in page-mapping array (subfunction 03h only)
array pointed to by ES:DI receives mapping info (AL=00/02)
80h internal error
81h hardware malfunction
84h undefined function requested
8Fh undefined subfunction parameter
A3h contents of source array corrupted (EMS 4.0?)
Note: this function was designed to be used by multitasking operating systems
and should not ordinarily be used by appplication software.
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - GET/SET PARTIAL PAGE MAP
AH = 4Fh
AL = subfunction
00h get partial page map
DS:SI = pointer to structure containing list of segments whose
mapping contexts are to be saved
ES:DI = pointer to array to receive page map
01h set partial page map
DS:SI = pointer to structure containing saved partial page map
02h get size of partial page map
BX = number of mappable segments in the partial map to be saved
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
84h undefined function requested
8Bh one of specified segments is not mappable
8Fh undefined subfunction parameter
A3h contents of partial page map corrupted or count of mappable
segments exceeds total number of mappable segments in system
AL = size of partial page map for subfunction 02h
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - MAP/UNMAP MULTIPLE HANDLE PAGES
AH = 50h
AL = subfunction
00h
01h
DX = handle
CX = number of entries in array
DS:SI = pointer to mapping array
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
8Ah one or more logical pages are invalid
8Bh one or more physical pages are invalid
8Fh invalid subfunction
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - REALLOCATE PAGES
AH = 51h
DX = handle
BX = number of pages to be allocated to handle
Return: BX = actual number of pages allocated to handle
AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
87h more pages requested than present in system
88h more pages requested than currently available
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - GET/SET HANDLE ATTRIBUTES
AH = 52h
AL = subfunction
00h get handle attributes
01h set handle attributes
BL = new attribute (see returned AL)
02h get attribute capability
DX = handle
Return: AL = attribute (for subfunction 00h)
00h handle is volatile
01h handle is nonvolatile
AL = attribute capability (for subfunction 02h)
00h only volatile handles supported
01h both volatile and non-volatile supported
AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
8Fh undefined subfunction
90h undefined attribute type
91h feature not supported
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - GET/SET HANDLE NAME
AH = 53h
AL = subfunction
00h get handle name
ES:DI = pointer to 8-byte handle name array
01h set handle name
DS:SI = pointer to 8-byte handle name
DX = handle
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
83h invalid handle
84h undefined function requested
8Fh undefined subfunction
A1h duplicate handle name
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - GET HANDLE DIRECTORY
AH = 54h
AL = subfunction
00h get handle directory
ES:DI = pointer to buffer for handle directory
01h search for named handle
DS:SI = pointer to 8-byte name
02h get total number of handles
Return: AL = number of entries in handle directory (subfunction 00h)
DX = value of named handle (subfunction 01h)
BX = total number of handles (subfunction 02h)
AH = status
00h successful
80h internal error
81h hardware malfunction
84h undefined function requested
8Fh undefined subfunction
A0h no such handle name
A1h a handle found had no name
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - ALTER PAGE MAP AND JUMP
AH = 55h
AL = subfunction
00h physical page numbers provided by caller
01h segment addresses provided by caller
DX = handle
DS:SI = pointer to structure containing map and jump address
Return: (at target address unless error)
AH = status
00h successful
80h internal error
81h hardware failure
83h invalid handle
84h undefined function requested
8Ah invalid logical page number encountered
8Bh invalid physical page number encountered
8Fh invalid subfunction
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - ALTER PAGE MAP AND CALL
AH = 56h
AL = subfunction
00h physical page numbers provided by caller
DX = handle
DS:SI = pointer to structure containing page map and call address
01h segment addresses provided by caller
DX = handle
DS:SI = pointer to structure containing page map and call address
02h get page map stack space required
Return: (if successful, the target address is called. Use a RETF to return and
restore mapping context)
BX = stack space required (subfunction 02h)
AH = status
00h successful
80h internal error
81h hardware failure
83h invalid handle
84h undefined function requested
8Ah invalid logical page number encountered
8Bh invalid physical page number encountered
8Fh undefined subfunction
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - MOVE/EXCHANGE MEMORY REGION
AH = 57h
AL = subfunction
00h move memory region
01h exchange memory region
DS:SI = pointer to structure describing source and destination
Return: AH = status
00h successful
80h internal error
81h hardware failure
83h invalid handle
84h undefined function requested
8Ah invalid logical page number encountered
8Fh undefined subfunction
92h successful, but a portion of the source region has been
overwritten
93h length of source or destination region exceeds length of region
allocated to either source or destination handle
94h conventional and expanded memory regions overlap
95h offset within logical page exceeds size of logical page
96h region length exceeds 1M
97h source and destination EMS regions have same handle and overlap
98h memory source or destination type undefined
A2h attempted to wrap around 1M conventional address space
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - GET MAPPABLE PHYSICAL ADDRESS ARRAY
AH = 58h
AL = subfunction
00h get mappable physical address array
ES:DI = pointer to buffer to be filled with array
01h get number of entries in m.p.a. array
Return: CX = number of entries in array
AH = status
00h successful
80h internal error
81h hardware failure
84h undefined function requested
8Fh undefined subfunction
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - GET EXPANDED MEMORY HARDWARE INFORMATION
AH = 59h
AL = subfunction
00h get hardware configuration array
ES:DI = pointer to buffer to be filled with array
01h get unallocated raw page count
Return: BX = unallocated raw pages (subfunction 01h)
DX = total raw pages (subfunction 01h)
AH = status
00h successful
80h internal error
81h hardware failure
84h undefined function requested
8Fh undefined subfunction
A4h access denied by operating system
Note: subfunction 00h is for use by operating systems only, and can be
enabled or disabled at any time by the operating system
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - ALLOCATE STANDARD/RAW PAGES
AH = 5Ah
AL = subfunction
00h allocate standard pages
01h allocate raw pages
BX = number of pages to allocate
Return: DX = handle
AH = status
00h successful
80h internal error
81h hardware failure
84h undefined function requested
85h no more handles available
87h insufficient memory pages in system
88h insufficient memory pages available
8Fh undefined subfunction
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - ALTERNATE MAP REGISTER SET
AH = 5Bh
AL = subfunction
00h get alternate map register set
01h set alternate map register set
BL = new alternate map register set number
ES:DI = pointer to map register context save area if BL=0
02h get alternate map save array size
03h allocate alternate map register set
04h deallocate alternate map register set
BL = number of alternate map register set
Return: BL = current active alternate map register set number if nonzero (AL=0)
ES:DI = pointer to a map register context save area if BL=0 (AL=0)
DX = array size in bytes (subfunction 02h)
BL = number of alternate map register set; zero if not supported (AL=3)
AH = status
00h successful
80h internal error
81h hardware malfunction
84h undefined function requested
8Fh undefined subfunction
9Ah specified alternate map register set not supported
9Bh all alternate map register sets currently allocated
9Ch alternate map register sets not supported
9Dh undefined or unallocated alternate map register set
A3h source array corrupted
A4h operating system denied access
Note: this function is for use by operating systems only, and can be
enabled or disabled at any time by the operating system
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - ALTERNATE MAP REGISTER SET - DMA REGISTERS
AH = 5Bh
AL = subfunction
05h allocate DMA register set
06h enable DMA on alternate map register set
BL = DMA register set number
DL = DMA channel number
07h disable DMA on alternate map register set
BL = DMA register set number
08h deallocate DMA register set
BL = DMA register set number
Return: BL = DMA register set number; zero if not supported (subfunction 05h)
AH = status
00h successful
80h internal error
81h hardware malfunction
84h undefined function requested
8Fh undefined subfunction
9Ah specified DMA register set not supported
9Bh all DMA register sets currently allocated
9Ch alternate DMA sets not supported
9Dh undefined or unallocated DMA register set
9Eh dedicated DMA channels not supported
9Fh specified dedicated DMA channel not supported
A3h source array corrupted
A4h operating system denied access
Note: this function is for use by operating systems only, and can be
enabled or disabled at any time by the operating system
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - PREPARE EXPANDED MEMORY HARDWARE FOR WARM BOOT
AH = 5Ch
Return: AH = status
00h successful
80h internal error
81h hardware malfunction
84h undefined function requested
-----------------------------------------------------------
INT 67 - LIM EMS 4.0 - ENABLE/DISABLE OS FUNCTION SET FUNCTIONS
AH = 5Dh
AL = subfunction
00h enable OS Function Set
01h disable OS Function Set
02h return access key (resets memory manager, returns access key at
next invocation)
BX,CX = access key returned by first invocation
Return: BX,CX = access key, returned only on first invocation of function
AH = status
00h successful
80h internal error
81h hardware malfunction
84h undefined function requested
8Fh undefined subfunction
A4h operating system denied access
-----------------------------------------------------------
INT 67 - LIM EMS ??? - GET PHYSICAL WINDOW ARRAY
AH = 60h
???
Return: ???
-----------------------------------------------------------
INT 68 -> unused
-----------------------------------------------------------
INT 69 -> unused
-----------------------------------------------------------
INT 6A -> unused
-----------------------------------------------------------
INT 6B -> unused
-----------------------------------------------------------
INT 6C - system resume vector (CONVERTIBLE)
- DOS 3.2 Realtime Clock update
-----------------------------------------------------------
INT 6D -> unused
-----------------------------------------------------------
INT 6E -> unused
-----------------------------------------------------------
INT 6F -> unused
-----------------------------------------------------------
INT 70-77 -> AT/XT286/PS50+ VECTORED HARDWARE LINES
IRQ8 real-time clock
IRQ9 LAN adapter 1 (rerouted to INT 0Ah by BIOS)
IRQ10 reserved
IRQ11 reserved
IRQ12 (PS50+) mouse interrupt
IRQ13 80287 error (rerouted to INT 2 by BIOS)
IRQ14 fixed disk
IRQ15 reserved
-----------------------------------------------------------
INT 78 -> not used
-----------------------------------------------------------
INT 79 -> not used
-----------------------------------------------------------
INT 7A -> not used
-----------------------------------------------------------
INT 7B -> not used
-----------------------------------------------------------
INT 7C -> not used
-----------------------------------------------------------
INT 7D -> not used
-----------------------------------------------------------
INT 7E -> not used
-----------------------------------------------------------
INT 7F -> not used
-----------------------------------------------------------
INT 80 -> reserved for BASIC
-----------------------------------------------------------
INT 81 -> reserved for BASIC
-----------------------------------------------------------
INT 82 -> reserved for BASIC
-----------------------------------------------------------
INT 83 -> reserved for BASIC
-----------------------------------------------------------
INT 84 -> reserved for BASIC
-----------------------------------------------------------
INT 85 -> reserved for BASIC
-----------------------------------------------------------
INT 86 -> Relocated (by NETBIOS) INT 18
-----------------------------------------------------------
INT 86-F0 -> used by BASIC while in interpreter
-----------------------------------------------------------
INT E0 - CP/M-86 function calls
-----------------------------------------------------------
INT E4 - Logitech Modula v2.0 - MonitorEntry
AX = 0005h
BX = priority
-----------------------------------------------------------
INT E4 - Logitech Modula v2.0 - MonitorExit
AX = 0006h
-----------------------------------------------------------
INT F1 - reserved for user interrupt
-----------------------------------------------------------
INT F2 - reserved for user interrupt
-----------------------------------------------------------
INT F3 - reserved for user interrupt
-----------------------------------------------------------
INT F4 - reserved for user interrupt
-----------------------------------------------------------
INT F5 - reserved for user interrupt
-----------------------------------------------------------
INT F6 - reserved for user interrupt
-----------------------------------------------------------
INT F7 - reserved for user interrupt
-----------------------------------------------------------
INT F8 - 10 ms INTERVAL TIMER (TANDY???)
-----------------------------------------------------------
INT F9 - reserved for user interrupt
-----------------------------------------------------------
INT FA - USART READY (RS-232C) (TANDY???)
-----------------------------------------------------------
INT FB - USART Rx READY (keyboard) (TANDY???)
-----------------------------------------------------------
INT FC - reserved for user interrupt
-----------------------------------------------------------
INT FD - reserved for user interrupt
-----------------------------------------------------------
INT FE - destroyed by return from protected mode on PC/AT
-----------------------------------------------------------
INT FF - destroyed by return from protected mode on PC/AT
-----------------------------------------------------------