!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		; push the location of the text
	pha					;   to display onto the stack
	lda #< message
	pha
	jsr print_string	; call the actual print subroutine
	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			; flashing gobbledygook garbage (scat)

	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:
	tsx					; load the stack pointer
	inx					;   traverse upwards to our arguments
	inx
	inx
	lda stack, x		; copy the arguments on the stack
	sta PSL + 1			;   on top of the instruction that
	inx					;   needs to point to the text
	lda stack, x
	sta PSL + 2
	ldx #$00

PSL	lda $0000, x		; this instruction's operand is
						;   modified by the code above

	cmp #$0				; return on null terminator
	beq +
	sta screen + rowlen, x
	inx
	jmp PSL
+	rts

message !scr "welcome to scat os", 0