play.asm

很好的键盘驱动代码

code    segment
        assume  cs:code,ds:code
        org     100h
start:  jmp     go

readkey proc    near
        xor     ah,ah
        int     16h
        ret
readkey endp

sing    proc    near
        push    ax
        push    cx
        mov     al,0b6h
        out     43h,al
        xor     al,al
        shr     ah,1
        out     42h,al
        mov     al,ah
        out     42h,al
        in      al,61h
        mov     ah,al
        or      al,3
        out     61h,al
        xor     cx,cx
        mov     al,0f0h                
next:
        loop    next
        dec     al
        jnz     next
        mov     al,ah
        out     61h,al
        pop     cx
        pop     ax
        ret
sing    endp

go:
        call    readkey
        cmp     ax,11bh
        jz      over
        call    sing
        jmp     go
over:
        mov     ah,4ch
        int     21h
code    ends
end     start