!source "constants.s"
!source "basic-boot.s"
+start_at $0900

	sei				; no interrupts pls

	ldx #$00		; Screen colours
	stx bdcol
	ldx #$08
	stx bgcol

	jsr $e544		; clear screen
	
	;lda < message		; print message
	;pha
	;lda > message
	;pha
	jsr print_string
	;pla
	;pla

	ldx #$01		; start triangle wave
	ldy #$11
	stx ch1_freq_hi
	sty ch1_freq_lo
	ldx #$11
	stx ch1_ctl
	
.loop
	inc bdcol

	lda inputb		; Scans the keyboard buffer
	cmp #$EF		; If user presses Space ($ef) then quit
	bne .loop

	ldx #$08		; kill sound
	stx ch1_ctl

	rts

print_string:
	;lda	message
	;sta PSL + 2
	;lda > message
	;sta PSL + 1
	
	ldx #$00
PSL	lda message, x
	cmp #$0			; return on null terminator
	beq +
	sta screen + rowlen, x
	inx
	jmp PSL
+	rts

message !scr "welcome to scat os", 0