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;______________________________________________________________________________________________________
;Wait for keyboard keypress
;IN: 	nothing
;OUT:	CF sets on keyup and CF clears on keydown
;	AL ASCII code
;	AH SCAN code
waitKeyboard:
	push ebx
	mov byte[kbdHandler.keyboardChanged], 0
.keyLoop:
	cmp byte[kbdHandler.keyboardChanged], 1		;Check if key press
	jne .keyLoop


	mov ah, bl			;BL contains scancode
	mov al, ah
	
	bt ax, 7			;Check if keyup
	jc .end
  
	;Check if shift is pressed
	cmp al, 54			;Right shift key
	je .shiftSet
	cmp al, 42			;Left shift key
	je .shiftSet
	jmp .next
.shiftSet:
	mov byte[.shiftFlag], 1		;.shiftFlag variable indicated weather shift is pressed or released
	mov al, 0
	stc
	jmp .actualEnd
.next:
	cmp byte[.shiftFlag], 1		;Use shift key characters if shift is pressed
	je .shiftIsSet
	
	 	
	
	movzx ebx, al
	add ebx, .keys			;Index scan code in Keys array
	mov al, byte[ebx]
	clc
	jmp .actualEnd
.shiftIsSet:
	movzx ebx, al
	add ebx, .keysShift		;Index scan code in shift-Keys array
	mov al, byte[ebx]
	clc
	jmp .actualEnd
;Now we have to check if shift is released 
.end:
	stc
	cmp al, 182			;Right shift released
	je .noShift
	cmp al, 170			;Left shift released
	je .noShift

	mov al, 0
	stc
	jmp .actualEnd
.noShift:
	mov al, 0
	mov byte[.shiftFlag], 0
	stc
.actualEnd:
	pop ebx	
	ret

;--------Variables----------;
.shiftFlag:
	db 0
.keys:
	db 27,0, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', 8, 9, 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']'
	db 13, 29, 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', "'", '`', 42, '\', 'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/'
	db 54, 55, 56, ' '
.keysShift:
	db 27,0, '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+', 8, 9, 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}'
	db 13, 29, 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '"', '~', 42, '|', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', '>', '?'
	db 54, 55, 56, ' '
;_________________________________________________________________________________________________

Code: Select all

Keyboard interrupt IRQ 1
kbdHandler:
	push eax
	xor eax,eax

	in al,0x60
 
.next:	
        cmp byte[.keyboardChanged], 0		;If any code is waiting for keyboard
	je .send				;send it in BL
	jmp .end
.send:
	mov bl, al
.end:
	mov byte[.keyboardChanged], 1

	mov al, 0x20
	out 0x20, al
	pop eax
	iret

.keyboardChanged:	db 0

Code: Select all

;Keyboard interrupt IRQ 1
kbdHandler:
	push eax
	xor eax,eax

	in al,0x60
 
	mov byte[.scanCode], al
	mov byte[.keyboardChanged], 1

	mov al, 0x20
	out 0x20, al
	pop eax
	iret

.keyboardChanged:	db 0
.scanCode		db 0