88 lines
1.0 KiB
Plaintext
88 lines
1.0 KiB
Plaintext
;Reads a keypress and prints its BIOS keycode.
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keycode:
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;Read a keypress
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mov ah, 0x0
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int 0x16
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;Store the keycode
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mov [.scan], ah
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mov [.ascii], al
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;Print the prefix
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mov si, .prefix
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call printstr
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;Convert the scancode to a hex string
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mov al, [.scan]
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mov di, .keycode
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call .byte2hex
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;Convert the ascii value to a hex string
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mov al, [.ascii]
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mov di, .keycode
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add di, 0x2
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call .byte2hex
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;Print the keycode
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mov si, .keycode
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call println
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ret
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.prefix db "0x", 0x0
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.scan db 0x0
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.ascii db 0x0
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.keycode times 0x5 db 0x0
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.byte2hex:
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;Store the initial registers in the stack
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push si
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push ax
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push bx
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push cx
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;Move the byte to AH
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mov ah, al
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;Set a key for the hex digits
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mov si, .key
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;Set a counter for the two hex digits
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mov cx, 0x2
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.loop:
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;Read a nibble
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rol ax, 0x1
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rol ax, 0x1
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rol ax, 0x1
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rol ax, 0x1
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mov bx, ax
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;Convert the nibble to a hex digit
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and bx, 0xf
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mov bl, [si + bx]
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;Store the hex digit
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mov [di], bl
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;Repeat
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inc di
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dec cx
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jnz .loop
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;Load the initial registers from the stack
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pop cx
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pop bx
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pop ax
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pop si
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ret
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.key db "0123456789abcdef"
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