assembly - ASM 用 ASCII 字符替换扫描码

Question

我有这个代码：

bits 16

org 0x7C00
start: jmp main

key: dw 0x1e, 'a', 0x30, 'b'

print:
    mov ah, 0x0E
    int 0x10

keyboard:
    cli
    in al, 0x64
    test al, 1
    jz return
    test al, 0x20
    jnz return

    in al, 0x60

    call convert

    call print
    sti

convert:
    mov bx, 0
    .LOOP:
        cmp al, [key+bx]
        je .conv
        add bx, 2
        jmp .LOOP
    .conv:
        mov al, [key+bx+1]
        ret

return:
    ret

main:
    call keyboard
    jmp main

times 510 - ($-$$) db 0
dw 0xAA55

它检查按键，每次我按下一个键时，我都会将它保存到注册 al 然后想打印出来。

但它只是被保存的扫描码，我需要用 ASCII 字符替换它，我用数组“键”来做，但它不起作用，只打印出 1 个键，然后程序就滞后了。

Answer 1

我通过分离 keydowns 和 keyups 来修复它 代码：

bits 16

org 0x7C00
mov cl, 0
start: jmp main

keydown: db 0x1e, 'a', 0x30, 'b'

keyup: db 0x9e, 'a', 0xb0, 'b'

print:
    mov ah, 0x0E
    int 0x10

keyboard:
    cli
    in al, 0x64
    test al, 1
    jz return
    test al, 0x20
    jnz return

    in al, 0x60

    cmp cl, 0
    je keypress
    jmp keyrelease

keyrelease:
    mov cl, 0
    sti
    ret

keypress:
    mov cl, 1
    call convert
    call print
    sti
    ret

convert:
    mov bx, 0
    .LOOP:
        cmp al, [keydown+bx]
        je .conv
        add bx, 2
        jmp .LOOP
    .conv:
        mov al, [keydown+bx+1]
        ret

return:
   ret

main:
    call keyboard
    jmp main

    times 510 - ($-$$) db 0
    dw 0xAA55