ds: autogen graphcis code

demosplash/Makefile

@@ -54,6 +54,7 @@ musictest.o:	musictest.s \
 	pt3_lib_play_frame.s pt3_lib_write_frame.s \
 	interrupt_handler.s \
 	missing.s k_40_48d.inc missing_screen_update.s \
+	create_update_type1.s \
 	dya_space_demo2.pt3
 	ca65 -o musictest.o musictest.s -l musictest.lst
 

demosplash/NOTES

@@ -67,7 +67,8 @@ Memory Map
 ~~~~~~~~~~
 0000-00ff		zero page
 0100-01ff		stack
-0200-02ff		?????
+0200			fake store for graphics update
+0201-02ff		?????
 0300-03ff		nibble table, irq vectors
 0400-07FF		lores page1
 0800-0bff		lores page2

demosplash/create_update_type1.s

@@ -0,0 +1,69 @@
+
+	; Autogenerates code that does interleaved Page0/Page1 lores mode
+	; but leaving room for 14 pixels/line of per-scanline color
+
+UPDATE_START = $9000
+
+create_update_type1:
+	ldx	#192
+	lda	#<UPDATE_START
+	sta	OUTL
+	lda	#>UPDATE_START
+	sta	OUTH
+	lda	#<one_scanline
+	sta	INL
+	lda	#>one_scanline
+	sta	INH
+create_update_outer_loop:
+	ldy	#0
+create_update_inner_loop:
+	lda	(INL),Y
+	sta	(OUTL),Y
+	iny
+	cpy	#49
+	bne	create_update_inner_loop
+
+	; toggl PAGE0/PAGE1
+	txa
+	and	#$1	; ror?
+	clc
+	adc	#$54
+	ldy	#1
+	sta	(OUTL),Y
+
+	clc
+	lda	#49
+	adc	OUTL
+	sta	OUTL
+	lda	OUTH
+	adc	#0
+	sta	OUTH
+
+	dex
+	bne	create_update_outer_loop
+
+	ldy	#0
+	lda	#$60
+	sta	(OUTL),Y
+
+	rts
+
+one_scanline:
+.byte	$2C,$54,$C0	; bit	PAGE0	; 4
+.byte	$A9,$0B		; lda	#$0b	; 2
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$8D,$00,$02	; sta	$200	; 4
+.byte	$A5,$FA		; lda	TEMP    ; 3
+

demosplash/missing.s

@@ -18,6 +18,11 @@ missing_intro:
 	lda	#0
 	sta	DRAW_PAGE
 
+	;=============================
+	; setup graphics code
+
+	jsr	create_update_type1
+
 	;=============================
 	; Load graphic page0
 
@@ -130,17 +135,20 @@ mloopB:	dex								; 2
 
 missing_display_loop:
 
-.include "missing_screen_update.s"
+	jsr	$9000		; update_type1
+;.include "missing_screen_update.s"
 
 	;======================================================
 	; We have 4550 cycles in the vblank, use them wisely
 	;======================================================
 	; do_nothing should be
 	;	4550
-	;	  -6
+	;	 -12 jsr/ret to update_type1
-	;        -10
+	;	  -6 jsr do_nothing_missing
+	;        - 7 check keypress
+	;	 - 3 jmp loop
 	;=============
-	;       4534
+	;       4522
 
 	jsr	do_nothing_missing			; 6
 
@@ -158,32 +166,23 @@ missing_no_keypress:
 	;=================================
 	; do nothing
 	;=================================
-	; and take 4534-6 = 4528 cycles to do it
+	; and take 4522 cycles to do it
 
 
 	; blah, current code the tight loops are right at a page boundary
 
 do_nothing_missing:
 
-	; want 4528-12=4516
+	; want 4522-6 (return)=4516
 
-	; Try X=4 Y=174 cycles=4525 R3 -3 X loops
+	;Try X=99 Y=9 cycles=4510 R6
 
-	; Try X=3 Y=215 cycles=4516
+	nop
+	nop
+	nop
 
-	nop		; 2
+	ldy	#9							; 2
-	nop		; 2
+gloop1:	ldx	#99							; 2
-
-	nop		; 2
-	nop		; 2
-
-	nop		; 2
-	nop		; 2
-
-
-
-	ldy	#215							; 2
-gloop1:	ldx	#3							; 2
 gloop2:	dex								; 2
 	bne	gloop2							; 2nt/3
 	dey								; 2

demosplash/musictest.s

@@ -199,6 +199,7 @@ wait_until_keypressed:
 .include "interrupt_handler.s"
 .include "pt3_lib_play_frame.s"
 .include "pt3_lib_write_frame.s"
+.include "create_update_type1.s"
 
 PT3_LOC = song