meh

jacme/jimmy.s

@@ -0,0 +1,56 @@
+!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