从键盘输入字符串，如是 小写字母，则转为大写字母输出。如是大写字母，原样输出。并约定，键入复位键[ESC]中止输入。例：输入： deddeDEDG 按复位键[ESC] 输出：deddededg

data segment
string db 10 dup(?)

str db 10 dup(?)
data ends

code segment
assume cs:code,ds:data
main proc far
mov ax,data
mov ds,ax
mov cx,10
lea di,str
lea si,string
get: mov ah,01h
int 21h
cmp al,1bh
jz done
mov byte ptr[si],al
inc si
loop get
done:lea si,string
again:mov al,[si]
cmp al,61h
jae next
mov byte ptr[di],al
jmp next1
next:
sub al,20h
mov byte ptr[di],al
next1:inc si
inc di
loop again
lea di,str
mov ah,02h
get1:mov dl,[di]

int 21h
inc di
loop get1
call nextline
ret
main endp

nextline proc near
mov dl ,0dh
mov ah,02h
int 21h
mov dl,0ah
mov ah,02h
int 21h
ret
nextline endp

code ends
end main

bW40VHoK.txt (925 Bytes)

[此贴子已经被作者于2006-7-4 17:30:41编辑过]

我刚刚写的
　esc1 = 1bh
en = 0dh
dseg segment
source db 10 dup(?)
welcome db "Please input Character: $"
varw dw ?
flag db 2
count db 0
dseg ends
cseg segment
assume cs:cseg,ds:dseg
start: mov ax,dseg
mov ds,ax
lea dx,welcome
mov ah,9
int 21h
call newline
lea si,source
mov varw,si
mov cx,10
OK: mov ah,1
int 21h
cmp al,esc1
jz done1;取消
cmp al,en
jnz ttt
mov cx,1
ttt: call ischar
inc count;小于10进行统计
cmp flag, 1
jnz next
sub al,20h ;
next: mov [si],al
inc si
loop OK
done1: call newline
mov si,varw
mov cx,0
mov cl,count
done: mov dl,[si]
mov ah,2
int 21h
inc si
loop done
mov ah,4ch
int 21h
ischar proc
cmp al,'A'
jb next1
cmp al,'Z'
ja next2
mov flag,0;为小写字母
ret
next2: cmp al,'a'
jb next1
cmp al,'z'
ja next1
mov flag,1;AL为大写字母
ret
next1: mov flag,-1;AL不为字母
ret
ischar endp
newline proc
push dx
push ax
mov dl,0dh
mov ah,2
int 21h
mov dl,0ah
mov ah,2
int 21h
pop ax
pop dx
ret
newline endp
cseg ends
end start