;ababc ;0b0bc ;0000c ;00000
data segment
mess1 db 13,10, 'input string:$' mess2 db 13,10, 'input a char:$' mess3 db 13,10, 'not found! $' mess4 db 13,10, 'found at: $'
org 40h
buff label byte max1 db 9 act1 db ?
stok1 db 9 dup(?) data ends
code segment
assume cs:code, ds:data main proc far push ds sub ax,ax push ax
mov ax,data mov ds,ax lea dx,mess1 mov ah,09
int 21h ;qust1? lea dx,buff mov ah,0ah int 21h ;ans1 call near ptr scan ret main endp scan proc near mov cl,act1 mov ch,0 mov dl,30h send: lea di,stok1
k1: cmp byte ptr[di],20h je kong
cmp byte ptr[di],13 je ones mov bl,[di]
mov byte ptr[di],20h
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k2:
inc dl inc di
cmp bl,[di] je cnum cnum:
mov byte ptr[di],0 ones:
mov ah,2 int 21h loop send kong: inc di jmp k1
mov si,di mov al,[si] cmp al,20h je next cmp al,[di] jne next inc dl next: inc di loop
next cmp repne scasb je found
nofd: lea dx,mess3 mov ah,9 int 21h jmp exit found: lea dx,mess4 mov ah,9 int 21h
sub act1, cl mov dl,act1 add dl,30h mov ah,2 int 21h
exit: ret scan endp
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code ends
end main
6.7 主程序从键盘输入一个八位的二进制数，对其作求补操作，用子程序对求补后的值以二进制形式显示。 code segment
assume cs:code main proc far start:
mov bx,0 mov cx,8 next: mov ah, 1 int 21h cmp al,30h jb exit cmp al,31h ja exit sub al,30h shl bl,1 add bl,al loop next neg bl call outp exit: mov ah,4ch int 21h main endp
outp proc near mov ah,2 mov dl,10 int 21h mov cx,8 kp: shl bl,1 jc k1 mov dl,30h jmp kk k1: mov dl,31h kk: mov ah,2 int 21h loop kp ret outp endp code ends end start
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6.8 主程序从键盘输入两个四位的十六进制数A和B，用子程序作十六进制计算A+B，并显示计算结果。
;only accept print char: 0~9,A~F code segment
assume cs:code main proc far start:
mov ax,cs mov ds,ax lea dx,mess mov ah,9 int 21h mov si,2 inone: mov dx,0 mov bx,0 mov ch,4 mov cl,4 next: mov ah, 1 int 21h sub al,30h cmp al,0 jb exit cmp al,9 ja char jmp k1 char: sub al,7 cmp al,0ah jb exit cmp al,0fh ja exit k1: mov dl,al shl bx,cl add bx,dx dec ch jnz next push bx mov ah,2 mov dl,13 int 21h mov ah,2 mov dl,10 int 21h dec si jnz inone
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call outp exit: mov ah,4ch int 21h main endp
outp proc near mov bp,sp
mov ax,[bp+2] mov bx,[bp+4] add bx,ax mov ch,4 mov cl,4 out1: rol bx,cl mov dx,bx and dl,0fh add dl,30h cmp dl,39h ja ad7 jmp kp ad7: add dl,7 kp: mov ah,2 int 21h dec ch jnz out1 ret outp endp
mess db 'only accept 0-9,A-F,input:',13,10,'$' code ends end start
6.9 某字数组为有符号数，第一个单元为元素个数N，后面为N个元素，编写通 用子程序，求数组元素中的最大值，并把它放入MAX单元。 ;put the big to max location data segment array dw 5,9,4,5,15,3 max dw ? data ends code segment
assume cs:code,ds:data main proc far
mov ax, data mov ds, ax mov cx, array lea bx, array+1
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