xmas24: add missing files

demos/xmas_2024/hgr_page_flip.s

@@ -0,0 +1,18 @@
+
+hgr_page_flip:
+	lda	DRAW_PAGE
+	beq	flip_to_page1
+
+flip_to_page2:
+	bit	PAGE2
+	lda	#0
+	beq	done_hgr_page_flip		; bra
+
+flip_to_page1:
+	bit	PAGE1
+	lda	#$20
+
+done_hgr_page_flip:
+        sta     DRAW_PAGE
+
+	rts

demos/xmas_2024/scroll_tables.s

@@ -0,0 +1,34 @@
+left_lookup_main:
+.byte $00,$00,$00,$00,$01,$01,$01,$01,$02,$02,$02,$02,$03,$03,$03,$03
+.byte $04,$04,$04,$04,$05,$05,$05,$05,$06,$06,$06,$06,$07,$07,$07,$07
+.byte $08,$08,$08,$08,$09,$09,$09,$09,$0A,$0A,$0A,$0A,$0B,$0B,$0B,$0B
+.byte $0C,$0C,$0C,$0C,$0D,$0D,$0D,$0D,$0E,$0E,$0E,$0E,$0F,$0F,$0F,$0F
+.byte $10,$10,$10,$10,$11,$11,$11,$11,$12,$12,$12,$12,$13,$13,$13,$13
+.byte $14,$14,$14,$14,$15,$15,$15,$15,$16,$16,$16,$16,$17,$17,$17,$17
+.byte $18,$18,$18,$18,$19,$19,$19,$19,$1A,$1A,$1A,$1A,$1B,$1B,$1B,$1B
+.byte $1C,$1C,$1C,$1C,$1D,$1D,$1D,$1D,$1E,$1E,$1E,$1E,$1F,$1F,$1F,$1F
+.byte $80,$80,$80,$80,$81,$81,$81,$81,$82,$82,$82,$82,$83,$83,$83,$83
+.byte $84,$84,$84,$84,$85,$85,$85,$85,$86,$86,$86,$86,$87,$87,$87,$87
+.byte $88,$88,$88,$88,$89,$89,$89,$89,$8A,$8A,$8A,$8A,$8B,$8B,$8B,$8B
+.byte $8C,$8C,$8C,$8C,$8D,$8D,$8D,$8D,$8E,$8E,$8E,$8E,$8F,$8F,$8F,$8F
+.byte $90,$90,$90,$90,$91,$91,$91,$91,$92,$92,$92,$92,$93,$93,$93,$93
+.byte $94,$94,$94,$94,$95,$95,$95,$95,$96,$96,$96,$96,$97,$97,$97,$97
+.byte $98,$98,$98,$98,$99,$99,$99,$99,$9A,$9A,$9A,$9A,$9B,$9B,$9B,$9B
+.byte $9C,$9C,$9C,$9C,$9D,$9D,$9D,$9D,$9E,$9E,$9E,$9E,$9F,$9F,$9F,$9F
+left_lookup_next:
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60
+.byte $00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60,$00,$20,$40,$60

demos/xmas_2024/vblank.s

@@ -0,0 +1,48 @@
+; wait for VBLANK
+
+; no way to do this on II/II+ short of vapor lock / floating bus
+; IIe you can read $C019 (in VBLANK when top bit 0)
+; IIc you can also read $C019 (also can setup interrupt)
+; IIgs you can read $C019 but reverse of IIe (in VBLANK when top bit 1)
+
+
+VBLANK	= $C019		;
+
+	; wait for vblank on IIe
+	; positive? during vblank
+
+; TODO: patch this to a RTS on non-IIe systems
+
+wait_vblank:
+;	Assume Apple IIe
+;	lda	APPLEII_MODEL
+;	cmp	#'e'
+;	bne	no_vblank
+
+; 4cade does this, the opposite of the way were doing it originally
+
+
+; $C019 on IIe high bit is VBL' or "negative if not in VBLANK"
+;	see page 66 in Sather's IIe
+
+wait_vblank_iie:
+	lda	VBLANK
+	bpl	wait_vblank_iie		; repeat until negative
+					; not in vblank
+wait_vblank_done_iie:
+	lda	VBLANK
+	bmi	wait_vblank_done_iie	; repeat until positive (start vblank)
+					; in vblank
+no_vblank:
+
+.if 0
+wait_vblank_iie:
+	lda	VBLANK
+	bmi	wait_vblank_iie		; wait for positive (in vblank)
+wait_vblank_done_iie:
+	lda	VBLANK			; wait for negative (vlank done)
+	bpl	wait_vblank_done_iie
+no_vblank:
+.endif
+
+	rts