用户按下键后程序显示垃圾

Question

我正在尝试在理想模式下使用 8086 汇编和 Turbo Assembler (TASM) 制作一架钢琴。当我运行一切都很好，当我点击一个键时有声音但是当我再次点击时整个屏幕打印垃圾数据。

你能看出这个 TASM 代码中的问题吗？

IDEAL
MODEL small
STACK 100h
DATASEG
Welcome db "Welcome! Just Try Clicking those buttons on your keyboard $"

CODESEG
start:
mov ax, @data
mov ds, ax
call printWelcome
jmp loopGetKey

loopGetKey:
call getKey
jmp loopGetKey

exit:
mov ax, 4c00h
int 21h

proc printWelcome
mov dx, offset Welcome
mov ah, 9
int 21h
ret
endp printWelcome

proc getKey
waitForKey:
;Check the status of the keyboard
mov ah, 1
int 16h
jz waitForKey
;read key
mov ah, 0
int 16h
;exit if ESC is pressed
cmp al, 1Bh
je exit
cmp al, 61h
je soundA
cmp al, 73h
je soundS
cmp al, 64h
je soundD
cmp al, 66h
je soundF
cmp al, 67h
je soundG
cmp al, 68h
je soundH
cmp al, 6Ah
je soundJ
cmp al, 6Bh
je soundK
cmp al, 6ch
je soundL
jne @continue

soundA:
push 2280
call makeSound
soundS:
push 2031
call makeSound
soundD:
push 1809
call makeSound
soundF:
push 1715
call makeSound
soundG:
push 1521
call makeSound
soundH:
push 1355
call makeSound
soundJ:
push 1207
call makeSound
soundK:
push 2031
call makeSound
soundL:
push 2031
call makeSound

@continue:

ret 
endp getKey 

proc makeSound
push bp
mov bp, sp
in al, 61h
or al, 00000011b
out 61h, al
mov al, 0b6h
out 43h, al
mov ax, [bp+4]
out 42h, al
mov al, ah
out 42h, al       
call delay
call stopSound
ret 4
endp makeSound

proc stopSound
push ax
in al, 61h
and al, 11111100b
out 61h, al 
pop ax
ret
endp stopSound

proc delay
push cx
push dx
push ax
mov     cx, 0FH
mov     dx, 4240H
mov     ah, 86H
int     15H
pop ax
pop dx
pop cx
ret
endp delay
END start

Answer 1

看看你的 proc 叫 'makeSound'，结束了。
您将 bp 推入堆栈，但没有将其弹出。大错特错。
您还使用 "ret 4" 而不是 2。它是 2，因为您在调用 proc 之前只按了一个词。

结尾应该是这样的：

    pop bp
    ret 2
endp makeSound

我还看到您在某些标签中使用了“@”。您应该使用其中的 2 个 (@@)。例如：

@@myLabel:
    **code**
    jmp @@myLabel

用户按下键后程序显示垃圾

Program displays garbage after user hits key

x86

assembly

dos

tasm

x86-16