汇编语言实验 子程序设计与系统调用

data segment para
MAXLEN DB 30
INPTLEN DB ?
STR1 DB 31 DUP(0)
STR2 DB 31 DUP(0);在此定义Dos功能9和0a共用的缓冲区
data ends

code segment para
assume cs:code,ds:data
main: mov ax,data
mov ds,ax
LEA DX,MAXLEN
MOV AH,0AH
INT 21H
XOR CX,CX
MOV CL,INPTLEN
LEA SI,STR1
LEA DI,STR2;①字符串输入
LOP1: MOV AL,[SI]
CALL UPCASE;②小写变大写子程序
MOV [DI],AL
INC DI
L6: INC SI
LOOP LOP1
MOV byte ptr [DI],'$'
CALL NEWLINE;③换行
LEA DX,STR2;④在新行显示转换后的字符串
mov ah,09H
int 21h
mov ah,1;按任意键结束
int 21h
mov ah,4ch
int 21h

NEWLINE PROC
PUSH AX
PUSH DX
MOV DL,0DH
MOV AH,02H
INT 21H
MOV DL,0AH
MOV AH,02H
INT 21H
POP DX
POP AX
RET
NEWLINE ENDP

upcase proc
cmp al,61h
jb tj
cmp al,7ah
ja tj
sub al,20h
tj:
ret
upcase endp

code ends
end main