Code Segment
Assume CS:Code,DS:Code
KBEsc equ 1BH
PromptStr DB 'Please input a letter(Esc to exit): $'
Start: push cs
pop ds ;使數據段與代碼段同段
Begin: lea dx,PromptStr
mov ah,9
int 21h
mov ah,1
int 21h
cmp al,KBEsc
jz Exit_Proc
mov cx,5
mov dl,al
mov ah,2
Disp_Chr: inc dl
int 21h
loop Disp_Chr
mov dl,13
int 21h
mov dl,10
int 21h
jmp Begin
Exit_Proc: mov ah,4ch ;結束程序
int 21h
Code ENDS
END Start ;編譯到此結束