47 lines
2.0 KiB
NASM
47 lines
2.0 KiB
NASM
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; Initialize text mode
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main:
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ldw a, 1 ; Mode: 1 for text mode
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ldw b, 800 ; Horizontal resolution
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ldw c, 600 ; Vertical resolution
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int 0x70 ; Initialize display
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ldw b, 0 ; Cursor position (character cell index)
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ldw c, 0xFFFFFF ; White color
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main_loop:
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; Get key down (handle key press/release)
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mov f, b ; f <- b
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int 0xF6 ; a <- keycode | b <- first press
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add b, f, ; b = f + b ; This moves the value in f back to B, and sence b is eyther 1 or 0, it will eyther increment it, or not increment it.
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str b, 0xEE
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str a, 0xEF
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; If a key is not pressed (register 0x1 == 0), continue the loop
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ldw d, 0 ; Check if a key is pressed (if register 0x1 == 1)
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beq a, d, main_loop ; If A == 0, loop back to main_loop (no key is pressed)
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; Render the character
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int 0x72 ; Render the character (using the keycode from register 0x0 at position b)
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; Write letter to disk at index ;push a
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; Write letter to disk at index ;push b
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; Write letter to disk at index ;push c
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; Write letter to disk at index ;push d
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; Write letter to disk at index ;
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; Write letter to disk at index ;ldw a, 8 ; disk number
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; Write letter to disk at index ;ldw b, 0 ; sector number
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; Write letter to disk at index ;ldr c, 0xEE ; byte offset
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; Write letter to disk at index ;ldr d, 0xEF ; value to write
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; Write letter to disk at index ;
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; Write letter to disk at index ;int 0x81 ; Write
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; Write letter to disk at index ;
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; Write letter to disk at index ;pop d
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; Write letter to disk at index ;pop c
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; Write letter to disk at index ;pop b
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; Write letter to disk at index ;pop a
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; Reset cursor to the top of the screen
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jmp main_loop ; Jump back to the main loop
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