实验二 汇编语言程序设计(顺序、多分支、循环)
目录
实验二 汇编语言程序设计(顺序、多分支、循环)
一. 实验目的
二. 实验内容
三. 实验过程和程序
四. 实验结果（包括必要的截图）
五.实验体会
注：模仿是最深的爱慕
实验二 汇编语言程序设计(顺序、多分支、循环)
一. 实验目的
1、掌握顺序和循环程序结构和设计方法；
2、熟悉在PC机上建立、汇编、连接、调试和运行8086/8088汇编语言程序的过程。
二. 实验内容
1、X、Y、Z、V均为字变量，在X、Y、Z、V字单元中存放是16位带符号数。试编写汇编语言程序完成以下功能：
①计算表达式值（V–（X*Y+Z-720））/X；
②将上述表达式运算结果整数放在SUM1单元，余数放在SUM2单元。
2、使用地址表实现如下功能：根据输入的数字1－7，分别显示相应的英文星期名，如果输入其他字符，则重新输入。
3、求一个班50名学生成绩的平均值、最大值和最小值,并将结果显示出来。
4、从键盘读入一个字符串，以Enter结束，字符串不超过50个字符，并打印该字符串；查找中间是否有‘masm’子串。如果有，输出‘Yes’；否则，输出‘No’)。
三. 实验过程和程序
;the source code of the Exp 2.1
stack segment stack
db 512 dup(?)
stack ends
data segment
inputX db "input x:",0ah,0dh,'$'
inputY db "input y:",0ah,0dh,'$'
inputZ db "input z:",0ah,0dh,'$'
inputV db "input v:",0ah,0dh,'$'
x dw 0
y dw 0
z dw 0
v dw 0
sum1 dw 0
sum2 dw 0
input db 8
db 1 dup(?)
db 8 dup(?)
sign db 0
outputSum1 db "sum1:",0ah,0dh,'$'
outputSum2 db "sum2:",0ah,0dh,'$'
data ends
code segment 'code'
assume cs: code, ds: data, ss: stack
start:
mov ax, data
mov ds, ax
mov ax, stack
mov ss, ax
mov ah, 09h
lea dx, inputX
int 21h
call readInt
mov word ptr [x], ax
mov ah, 09h
lea dx, inputY
int 21h
call readInt
mov word ptr [y], ax
mov ah, 09h
lea dx, inputZ
int 21h
call readInt
mov word ptr [z], ax
mov ah, 09h
lea dx, inputV
int 21h
call readInt
mov word ptr [v], ax
mov ax, [x]
mov bx, [y]
imul bx ; x*y
add ax, [z] ; x*y+z
sub ax, 720 ; x*y+z-720
mov bx, [v]
sub bx, ax ; v-(x*y+z-720)
mov ax, bx
cwd
mov bx, [x]
idiv bx ; (v-(x*y+z-720))/x
mov [sum1], ax
mov [sum2], dx
lea dx, outputSum1
mov ah, 09h
int 21h
mov ax, [sum1]
call prinIint
mov dl, 0ah
mov ah, 02h
int 21h
mov dl, 0dh
mov ah, 02h
int 21h
lea dx, outputSum2
mov ah, 09h
int 21h
mov ax, [sum2]
call prinIint
mov ah, 4ch
int 21h
readInt:
pushf
push bx
push cx
push dx
push si
lea dx, input
mov ah, 0ah
int 21h
mov dl, 0ah
mov ah, 02h
int 21h
mov dl, 0dh
mov ah, 02h
int 21h
mov ax, 0
xor cx, cx
mov cl, [input+1]
lea si, [input+2]
mov byte ptr [sign], 0
cmp byte ptr[si], '-'
jnz next1
inc si
dec cx
mov byte ptr [sign], 1
next1:
mov ax, 0
loop1:
mov bx, 10
mul bx
xor bx, bx
mov bl, [si]
sub bl, '0'
add ax, bx
inc si
loop loop1
cmp byte ptr [sign], 1
jnz next2
xor bx, bx
sub bx, ax
mov ax, bx
next2:
pop si
pop dx
pop cx
pop bx
popf
ret
prinIint:
pushf
push bx
push cx
push dx
push si
mov si, ax
cmp ax, 0
jge skip2
mov dl, '-'
mov ah, 02h
int 21h
mov ax, 0
sub ax, si
skip2:
cmp ax, 0
jne skip1
push ax
mov cx, 1
jmp next3_end
skip1:
mov cx, 0
next3:
cmp ax, 0
je next3_end
mov dl, 10
div dl
xor bx, bx
mov bl,ah
push bx
mov ah, 0
inc cx
jmp next3
next3_end:
xor dx, dx
pop dx
add dl, 48
mov ah, 02h
int 21h
loop next3_end
pop si
pop dx
pop cx
pop bx
popf
ret
code ends
end start
;the source code of the Exp 2.2
stack segment stack
db 512 dup(?)
stack ends
data segment
address dw l1, l2, l3, l4, l5, l6, l7
s1 db 'Monday $'
s2 db 'Tuesday $'
s3 db 'Wednesday $'
s4 db 'Thursday$'
s5 db 'Friday$'
s6 db 'Startday$'
s7 db 'Sunday$'
input db 'Please input a number between 1 to 7:',0ah,0dh,'$'
data ends
code segment 'code'
assume cs: code, ds: data, ss: stack
start:
mov ax, data
mov ds, ax
mov ax, stack
mov ss, ax
start1:
lea dx, input
mov ah, 09h
int 21h
mov ah, 01h
int 21h
mov bl, al
mov dl, 0ah
mov ah, 02h
int 21h
mov dl, 0dh
mov ah, 02h
int 21h
mov al, bl
sub al, '0'
cmp al, 1
jb start1
cmp al,7
ja start1
dec al
mov ah, 0
mov bx,ax
shl bx, 1
jmp address[bx]
l1:
lea dx,s1
jmp s
l2:
lea dx, s2
jmp s
l3:
lea dx, s3
jmp s
l4:
lea dx, s4
jmp s
l5:
lea dx, s5
jmp s
l6:
lea dx, s6
jmp s
l7:
lea dx, s7
s:
mov ah, 09h
int 21h
mov dl, 0ah
mov ah, 02h
int 21h
mov dl, 0dh
mov ah, 02h
int 21h
mov ah, 4ch
int 21h
code ends
end start
;the source code of the Exp 2.3
stack segment stack
db 512 dup(?)
stack ends
data segment
inputMSG db "input:", 0ah, 0dh, '$'
max dw 0
min dw 100
average dw 0
input db 8
db 1 dup(?)
db 8 dup(?)
sign db 0
output1 db "average:", 0ah, 0dh, '$'
output2 db "max:", 0ah, 0dh, '$'
output3 db "min:", 0ah, 0dh, '$'
data ends
code segment 'code'
assume cs: code, ds: data, ss: stack
start:
mov ax, data
mov ds, ax
mov cx, 50
L1:
lea dx, inputMSG
mov ah, 09h
int 21h
call readInt
cmp ax, [max]
jg max1
jmp skip11
max1:
mov [max], ax
skip11:
cmp [min], ax
jg min1
jmp skip22
min1:
mov [min], ax
skip22:
add [average], ax
loop L1
mov ax, [average]
cwd
mov bx, 50
idiv bx
mov [average], ax
lea dx, output1
mov ah, 09h
int 21h
mov ax, [average]
call printInt
mov dl, 0ah
mov ah, 02h
int 21h
mov dl, 0dh
mov ah, 02h
int 21h
lea dx, output2
mov ah, 09h
int 21h
mov ax, [max]
call printInt
mov dl, 0ah
mov ah, 02h
int 21h
mov dl, 0dh
mov ah, 02h
int 21h
lea dx, output3
mov ah, 09h
int 21h
mov ax, [min]
call printInt
mov ah, 4ch
int 21h
readInt:
pushf
push bx
push cx
push dx
push si
lea dx, input
mov ah, 0ah
int 21h
mov dl, 0ah
mov ah, 02h
int 21h
mov dl, 0dh
mov ah, 02h
int 21h
mov ax, 0
xor cx, cx
mov cl, [input+1]
lea si, [input+2]
mov byte ptr [sign], 0
cmp byte ptr[si], '-'
jnz next1
inc si
dec cx
mov byte ptr [sign], 1
next1:
mov ax, 0
loop1:
mov bx, 10
mul bx
xor bx, bx
mov bl, [si]
sub bl, '0'
add ax, bx
inc si
loop loop1
cmp byte ptr [sign], 1
jnz next2
xor bx, bx
sub bx, ax
mov ax, bx
next2:
pop si
pop dx
pop cx
pop bx
popf
ret
printInt:
pushf
push bx
push cx
push dx
push si
mov si, ax
cmp ax, 0
jge skip2
mov dl, '-'
mov ah, 02h
int 21h
mov ax, 0
sub ax, si
skip2:
cmp ax, 0
jne skip1
push ax
mov cx, 1
jmp next3_end
skip1:
mov cx, 0
next3:
cmp ax, 0
je next3_end
mov dl, 10
div dl
xor bx, bx
mov bl,ah
push bx
mov ah, 0
inc cx
jmp next3
next3_end:
xor dx, dx
pop dx
add dl, 48
mov ah, 02h
int 21h
loop next3_end
pop si
pop dx
pop cx
pop bx
popf
ret
code ends
end start
;the source code of the Exp 2.4
stack segment stack
db 512 dup(?)
stack ends
data segment
data2 db 50, ?, 50 dup('$')
string db 'yes', 0ah, 0dh, '$'
string1 db 'no', 0ah, 0dh, '$'
data ends
code segment
assume cs: code, ds: data, ss: stack
start:
mov ax, data
mov ds, ax
mov ax, stack
mov ss, ax
mov ah, 0ah
mov dx, offset data2
int 21h
mov ah, 02h
mov dl, 0ah
int 21h
mov ah, 02h
mov dl, 0dh
int 21h
mov dx, offset data2+2
mov ah, 09h
int 21h
mov ah, 02h
mov dl, 0ah
int 21h
mov ah, 02h
mov dl, 0dh
int 21h
mov al, 0h
mov cx, 47
mov di, 0
again:
mov al, [ di + 2 ]
cmp al, 61h
jnz next
mov al, [ di + 3]
cmp al, 73h
jnz next
mov al, [ di + 4 ]
cmp al, 6dh
jnz next
jmp yes
next:
add di, 1
loop again
mov dx, offset string1
mov ah, 09h
int 21h
jmp endcode
yes:
mov dx, offset string
mov ah, 09h
int 21h
endcode:
mov ax, 4c00h
int 21h
code ends
end start
四. 实验结果（包括必要的截图）
图 1 题2.1运行截图①
图 2 题2.1运行截图②
图 3 题2.2运行截图①
图 4 题2.2运行截图②
图 5 题2.3运行截图①
图 6 题2.3运行截图②
图 7 题2.4运行截图①
图 8 题2.4运行截图②
五.实验体会
汇编太难了，这四个题目如果不查资料一个都弄不出来。上课听得很过瘾，下课啥也不会做。