汇编程序练习
1.显示helloworld程序
data segmentstring DB 'Hello World!!',13,10,'$' data endscode segment assume cs:code,ds:data start:mov ax,datamov ds,axlea dx,stringmov ah,9int 21Hmov ah,4cHint 21h code endsend start
初始化程序段地址
mov ax,data
mov ds,ax
把字符串首地址送到DX
lea dx,string
调用DOS字符串显示功能
mov ah,9
int 21H
调用DOS返回功能
mov ah,4cH
int 21h
2.大小写转换
;特殊方法转换大小写，大写字母第五位为0，小写字母第五位为1 assume cs:codesg,ds:datasg datasg segmentDB 'BaSic'DB 'iNfOrMaTiOn' datasg endscodesg segment start:mov ax,datasgmov ds,axmov bx,0mov cx,5s: mov al,[bx]and al,11011111Bmov [bx],alinc bxloop smov bx,5mov cx,11s0: mov al,[bx]or al,00100000Bmov [bx],alinc bxloop s0mov ax,4c00Hint 21Hcodesg ends end start总结
