汇编小写字母转换为大写字母.doc

文档介绍：汇编小程序:小写字母转换成大写字母实验内容:接收键入字符(以CTRL-C为结束),将小写字母变为大写字母,并在屏幕上显示。DATASSEGMENTMESSAGEDB'etothesystem!',13,10,13,10DB'Thefunctionoftheprogramischangingsmallletterstocapitalletters.',13,10DB'Ifyouentercapitallettersornumberstherewillbenochanges.',13,10,13,10DB'Pleaseenterastring.',13,10,'$'CRDB13,10,'$';回车换行STRINGDB100DB0DB80DUP(0);定义缓冲区AGAINDB'Doyouwanttotryagain?(YorN)',13,10,'$'ERRORDB'ERROR!',13,10,'momds.',13,10,'$';错误提示DATASENDSSTACKSSEGMENTDB200DUP(?)STACKSENDSCODESSEGMENTASSUMECS:CODES,DS:DATAS,SS:STACKSSTART:HEAD:MOVAX,DATASMOVDS,AXLEADX,MESSAGE;输出提示语MOVAH,09HINT21HLEADX,STRINGMOVAH,0AHINT21H;把字符串输入到BUF区LEADX,CRMOVAH,09HINT21H;以上为回车换行LEASI,STRING+2;把字符串首地址存入BXMOVCL,STRING+1;把字符个数存CXMOVCH,0NEXT1:MOVDL,[SI]CMPDL,'a'JBNEXT2CMPDL,'z'JANEXT2;ASCII码小于a和大于z的跳过,其余的减32SUBDL,20H;大小写字母的ASCII码差32NEXT2:MOVAH,02HINT21HINCSI;BX自加,X;CX自减,最终将是0JNENEXT1;CX非零时,