; conio.inc
; real mode console input / output functions
; Author: Josh Holtrop
; Date: 01/04/05
; Modified: 01/04/05


con_getkey:
	xor	ax, ax
	int	0x16
	ret


con_move_cursor:		;con_move_cursor(word location)
	push	bp
	mov	bp, sp
	push	ax

	mov	ax, [bp + 4]
	mov	[cursor], ax
	call	con_write_cursor

	pop	ax
	pop	bp
	ret


con_clear:
	pusha

	mov	ax, 0xB800
	mov	es, ax
	mov	di, 0
	mov	ax, 0x0720
	mov	cx, 2000
	rep stosw
	mov	[cursor], word 0
	call	con_write_cursor

	popa
	ret


con_putstring:			;con_putstring(char *str)
	push	bp
	mov	bp, sp
	pusha

	mov	si, [bp + 4]
putstring_loop:
	lodsb
	or	al, al
	jz	putstring_done
	mov	ah, 0x07
	push	ax
	call	con_putc
	add	sp, 2
	jmp	putstring_loop

putstring_done:
	popa
	pop	bp
	ret


con_putc:			;con_putc(char chr)
	push	bp
	mov	bp, sp
	pusha
	
	mov	ax, 0xB800
	mov	es, ax
	mov	di, [cursor]	
	mov	ax, [bp + 4]
	cmp	al, 10
	jz	putc_return
	stosw
	jmp	putc_update
putc_return:
	mov	ax, di
	mov	bl, 160
	div	bl		; quotient in al, remainder in ah
	shr	ax, 8
	sub	di, ax
	add	di, 160
putc_update:
	mov	[cursor], di
	call	con_write_cursor
	popa
	pop	bp
	ret


con_write_cursor:
	pusha

	mov	ax, [cursor]
	shr	ax, 1

	mov	bl, al
	mov	dx, 0x03D4
	mov	al, 0x0E
	out	dx, al

	inc	dx
	mov	al, ah
	out	dx, al

	dec	dx
	mov	al, 0x0F
	out	dx, al

	inc	dx
	mov	al, bl
	out	dx, al

	popa
	ret


cursor:	dw 0