59 lines
1.5 KiB
NASM
59 lines
1.5 KiB
NASM
[BITS 16]
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global _print_char
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global _get_char
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global _check_key
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global _set_cursor
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global _get_cursor_pos
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global _set_cursor_pos
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segment _TEXT class=CODE
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_print_char:
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push bp
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mov bp, sp
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mov ah, 0x0E ; BIOS TTY write
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mov al, [bp+4] ; first arg: char c
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xor bh, bh ; page 0
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int 0x10
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pop bp
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ret
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_get_char:
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; Returns: AL = ASCII char, AH = scancode
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; Blocks until a key is pressed
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xor ah, ah ; Function 0: wait for keypress
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int 0x16
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xor ah, ah
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ret
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_check_key:
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; Non-blocking: returns ZF=1 if no key waiting
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mov ah, 0x01 ; Function 1: check buffer
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int 0x16
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jz .empty
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mov ax, 1
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ret ; ZF=0 means key available, AL/AH = key
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.empty:
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xor ax, ax
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ret
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_set_cursor:
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mov ah, 0x01
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mov cx, 0x0607
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ret
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_get_cursor_pos:
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mov ah, 0x03
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xor bh, bh
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int 0x10 ; DH = row, DL = col
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mov ax, dx ; DH->AH, DL->AL in one shot
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ret
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_set_cursor_pos:
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push bp
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mov bp, sp
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mov ah, 0x02 ; AH=02h: set cursor position
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xor bh, bh ; page 0
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mov dh, [bp+4] ; row
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mov dl, [bp+6] ; col
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int 0x10
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pop bp
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ret
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