微机实验模版

;check 程序段用于读取输入字符，并判断奇偶， ;若为奇数转入两数相加程序段，若为偶数转入两数相减程序段 again: lea dx,string2 mov ah,9 int 21h jmp check add_12: mov cx,0 mov si,0 mov bl,0 clc

looper1: inc cx mov al,mem2[si] add mem1[si],bl ;加上低位的进位 add mem1[si],al jc yc1 ;进位为1 jnc nc1 ;进位为0 yc1:mov bl,1 jmp return_add nc1:mov bl,0 jmp return_add ;将进位存入bl return_add: inc si cmp cx,3 jnz looper1 jmp next

sub_12: mov cx,0 mov si,0 mov bl,0 clc looper2: inc cx mov al,mem2[si] sub mem1[si],bl sub mem1[si],al jc yc2 ;借位为1 jnc nc2 ;借位为0 yc2:mov bl,1 jmp return_sub

nc2:mov bl,0 jmp return_sub ;将借位存入bl return_sub: inc si cmp cx,3 jnz looper2 jmp next next: mov di,0 mov si,2 mov cx,3 x1: mov al,mem1+si