實(shí)驗(yàn)三 字母的大小寫(xiě)轉(zhuǎn)換

3/3實(shí)驗(yàn)三字母的大小寫(xiě)轉(zhuǎn)換實(shí)驗(yàn)三字母的大小寫(xiě)轉(zhuǎn)換

一、實(shí)驗(yàn)要求：

顯示選擇項(xiàng)菜單，接收鍵盤(pán)輸入以確定大寫(xiě)轉(zhuǎn)小寫(xiě)，小寫(xiě)轉(zhuǎn)大寫(xiě)或返回DOS。然后根據(jù)提示輸入字符串（以回車為結(jié)束符），程序按先前選擇進(jìn)行大小寫(xiě)轉(zhuǎn)換并顯示，之后返回選擇項(xiàng)菜單。

二、實(shí)驗(yàn)?zāi)康模毫私庑?xiě)字母和大寫(xiě)字母在計(jì)算機(jī)內(nèi)的表示方法，并學(xué)習(xí)如何進(jìn)行轉(zhuǎn)換。

三、實(shí)驗(yàn)程序框圖：

四、實(shí)驗(yàn)程序：

CRLFMACRO

MOVAHM02H

MOVDL,0DH

INT21H

MOVAH,02H

調(diào)用DOS中斷接收鍵入的字符是3否開(kāi)始初始化

顯示提示信息返回DOS是1否是2否小寫(xiě)不變，大寫(xiě)變小寫(xiě)存入小寫(xiě)緩行區(qū)等待鍵入字母并顯示是回車否顯示小寫(xiě)緩存區(qū)內(nèi)容等待鍵入字線并顯示是回車否大寫(xiě)不變小寫(xiě)變大寫(xiě)存入大寫(xiě)緩行區(qū)顯示大寫(xiě)緩存區(qū)內(nèi)容

YYYYN

NN

MOVDL,0AH

INT21H

ENDM

DATASEGMENT

MESS1DB'capitallettertosmallletterinput1',0DH,0AHDB'smalllettertocapitalletterinput2',0DH,0AH

DB'backtoDOSinput3',0DH,0AH,'$'

MESS2DB'inputstring,sendenterstartconvert!',0DH,0AH,'$'MARKDB0

BUFDB82DUP(0)

DATAENDS

STACKSEGMENT

STADB50DUP(0)

TOPEQU50;LENGTHSTA

STACKENDS

CODESEGMENT

ASSUMECS:CODE,DS:DATA,ES:DATA,SS:STACK

START:MOVAX,DATA

MOVDS,AX

MOVES,AX

MOVAX,STACK;段寄存器和堆棧初始化

MOVSS,AX

MOVSP,TOP

MOVBX,OFFSETBUF;BX指向字符行緩沖區(qū)首址.KKK:MOVSI,0000H;偏移指針SI清0

MOVMARK,0

MOVAH,09H

LEADX,MESS1

INT21H

BG:MOVAH,08H

INT21H;接收鍵入字符

CMPAL,'3'

JEPPP;

CMPAL,'1'

JEBS

CMPAL,'2'

JESB

JMPBG

BS:MOVAH,09H;大寫(xiě)轉(zhuǎn)小寫(xiě)

LEADX,MESS2

INT21H

MOVMARK,11H

BS1:MOVAH,01H

INT21H

CMPAL,0DH

JEBBB

CMPAL,5AH

JATTT

CMPAL,41H

JBTTT

ADDAL,20H

JMPTTT

SB:MOVAH,09H;小寫(xiě)轉(zhuǎn)大寫(xiě)

LEADX,MESS2

INT21H

MOVMARK,22H

SB1:MOVAH,01H

INT21H

CMPAL,0DH

JZBBB

CMPAL,61H

JBTTT

CMPAL,7AH

JATTT;不是小寫(xiě)它母轉(zhuǎn)TTT

SUBAL,20H;小寫(xiě)字母轉(zhuǎn)化為大寫(xiě)字母TTT:MOV[BX+SI],AL;存入字符行緩沖區(qū)中INCSI;偏移指針加1

CMPMARK,11H

JEBS1

CMPMARK,22H

JESB1

JMPPPP

BBB:MOV[BX+SI],AL

MOVAL,0AH

MOV[BX+SI+1],AL;加入換行符

MOVAL,'$'

MOV[BX+SI+2],AL;再加一個(gè)`$`標(biāo)志字符

MOVAH,09H

MOVDX,BX

IN