homework23.asm

用汇编写的字符按键查看器

.286
.Model	Small
.Data

		;在这里添加内存变量定义

.Stack	100h
.Code
printONECHAR      proc
			cmp    al,	0ah
			jnb    printLETTER
			add	 al,	30h
			jmp    REALprint
printLETTER:      add    al,   37h
			jmp    REALprint
REALprint:		mov    ah,   0eh
                  int    10h
                  ret
printONECHAR      endp              

printASCII  	proc
			push   ax;只保留了al中值
			shr	 al,	04h
			call   printONECHAR
			pop    ax
			and    al,	0fh
			call 	 printONECHAR
			ret
printASCII        endp  

printSCAN		proc
			mov    al,	ah
			push   ax
			shr	 al,	04h 
		      call   printONECHAR 
		      pop    ax 
			and    al,	0fh
			call 	 printONECHAR
			ret
printSCAN         endp
start:
			mov 	 ax,	@data	;初始化数据段
			mov    ds,	ax
waitpress:		mov 	 ah,   0h
			int	 16h
			push	 ax
			mov	 ah,	0eh ;显示键入的字符
			int  	 10h
			cmp	 al,1bh
			jz	 exit
			mov    ah,   02h
			mov    dh,   08h
			mov    dl,   09h
			int    10h
			call   printASCII
			mov    ah,   02h
			mov    dh,   09h
			mov    dl,   09h
			int    10h
			pop    ax
			call   printSCAN
			mov    ax,   0e0dh;回车换行
			int    10h
			mov    ax,   0e0ah
			int    10h
			jmp    waitpress
	      	;TODO: 在这里添加你的代码
exit:		      mov	 ah,	4ch	;程序结束
		      int	 21h
end		      start