Mercurial > repos > ghero

view genesis.s68 @ 9:997690aa0507

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Improve method for choosing line palette entries. Read number of global and dynamic colors from image binary. Go back to doing a word, longword, word pattern of writes for turning off display, doing DMA and turning it back on again to make things work correctly on the real hardware.
author Mike Pavone <pavone@retrodev.com>
date Wed, 04 Sep 2013 00:41:52 -0700
parents 4ffd621f1d0c
children
line wrap: on
line source

	dc.l $0, start
	dc.l empty_handler
	dc.l empty_handler
	;$10
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$20
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$30
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$40
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$50
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$60
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$70
	dc.l HINT
	dc.l empty_handler
	dc.l VINT
	dc.l empty_handler
	;$80
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$90
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$A0
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$B0
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$C0
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$D0
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$E0
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	;$F0
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.l empty_handler
	dc.b "SEGA"
empty_handler:
	rte
start:
;background and sprite test

ButtonState	equ	$FFFFEFF0
ButtonStateNew	equ	ButtonState+2
PalAddress equ ButtonStateNew+2

CRAMXferSizeCmd equ $9308
CRAMDMACmd equ $C0000080
StaticColors equ 8

USE_HINT equ 0
	move.b  #$40, $A10009
	move.l	#$C00000, a4
	move.l	#$c00004, a5

	move.l	#$0, a7

	move.w	#$8004, (a5)
	move.w	#$8104, (a5)	;turn off display
	move.w	#$8200, (a5)	;Table A = 0000
	move.w	#$8400, (a5)	;Table B = 0000
	move.w	#$857C, (a5)	;Sprite Table = F800
	move.w	#$8B00, (a5)		;set full screen vertical and horizontal scrolling
	move.w  #$8C01, (a5)    ;H40 mode, no shadow/hilight, no interlace
	move.w	#$8D3F, (a5)	;H Scroll = FC00
	move.w	#$9001, (a5)	;64x32 scroll tables



	lea	BgData(pc), a0
	move.w	(a0)+, d0	;size in words
	move.w	(a0)+, d1	;width in cells
	move.w	(a0)+, d2	;height in cells
	move.w d2, d7

	subq	#1, d0		;adjust for 68K dbra routine
	move.w	#$8f02, (a5)	;autoincrement = 2
	move.l	#$50200000, (a5);beginning of background tile area
CopyTiles:
	move.w	(a0)+, (a4)	;copy tiles to VRAM
	dbra	d0, CopyTiles

	move.l	#$40000000, d4	;beginning of Plane A Name table
	move.l	#$00800000, d5	;delta between lines
	move.w	#$81, d6
	subq	#1, d1
	subq	#1, d2
	move.w	d1, d3
WriteNamesY:
	move.l	d4, (a5)
	move.w	d3, d1

WriteNamesX:
	move.w	d6, (a4)
	addq	#1, d6
	dbra	d1, WriteNamesX

	add.l	d5, d4
	dbra	d2, WriteNamesY

	move.l	#$C0000000, (a5)	;setup writes to CRAM
	move.b  (a0)+, d0			;Number of static colors
	move.b  (a0)+, d1			;Number of dynamic colors
	ext.w	d0
	move.w	d0, -(a7)
	beq		NoStatic
	subq.w	#1, d0
CopyColors:
	move.w	(a0)+, (a4)
	dbra	d0, CopyColors
	move.w	(a7)+, d0
NoStatic:

	move.l a0, (PalAddress).w


	move.l	#$60000010, (a5)	;setup writes to VSRAM
	move.w	#$0, (a4)		;vscroll = 0

	move.l	#$7C000003, (a5)	;setup writes to HScroll Table FC00
	move.w	#0, (a4)		;Plane A&B HScroll = 0;
	move.w	#0, (a4)		;

	move.l	#$78000003, (a5)	;clear sprite table
	move.l	#0, (a4)
	move.l	#0, (a4)

	move.w	#$8114, (a5)		;turn on DMA

	;bsr	InitSprites
	;bsr	AddSprite

	move.w	#$0, (a0)

	;bsr	LoadSpritePal
	;bsr	InitFrameBigSprite
	moveq	#0, d3
	;bsr	ChangeFrameBigSprite

	move.w	d0, d5
	ext.l   d5
	moveq	#17, d2
	lsl.l	d2, d5
	or.l	#CRAMDMACmd, d5		;setup DMA command word

	ext.w	d1
	beq		NoDynamic
	or.w	#$9300, d1
	move.w	d1, (a5)		;set Transfer length
	move.w	#$9400, (a5)

	move.w	#$8114, d6
	move.w	#$8174, d7

	if USE_HINT

		move.w	#$8014, (a5)
		move.w	#$8A00, (a5)		;HINT occurs on every line
	endif

	move.w	#$8174, (a5)
	move #$2300, SR


Loop:
	if USE_HINT
		bra Loop
	endif
WaitTop:
	cmpi.b  #$FF, 4(a5)
	bne.s   WaitTop

LineDone:
	move.b	4(a5), d0
WaitNextLine:
	cmp.b	4(a5), d0
	beq	WaitNextLine



HINT:
	move.w	d6, (a5)
	move.l	d5, (a5)		;start DMA
	move.w	d7, (a5)
	;move.l d6, (a5)
	;move.l d7, (a5)
	move.w d1, (a5)		;set Transfer length
	move.w	#$9400, (a5)

	if USE_HINT
		rte
	endif

	cmp.b	#223, 4(a5)
	beq	WaitTop

	bra	LineDone
NoDynamic:
	move.w	#$8174, (a5)
	move #$2300, SR
.loop
	bra .loop
VINT:
	move.w d1, -(a7)
	if USE_HINT
		move.w	#$8144, (a5)
	endif
	;bsr	SpriteCopyVRAM

	bsr	ReadPad

	;bsr	Player1Vint

	move.l	(PalAddress).w, d7			;setup DMA source address
	move.w	#$9500, d6
	ror.l	#1, d7
	move.b	d7, d6
	move.w	d6, (a5)
	ror.l	#8, d7
	move.b	d7, d6
	add.w	#$100, d6
	move.w	d6,(a5)
	ror.l	#8, d7
	move.b	d7, d6
	add.w	#$100, d6
	and.b	#$7F, d6
	move.w	d6,(a5)

	;move.l	d5, (a5)		;do DMA for first line

	move.w (a7)+, d1
	move.w	d1, (a5)		;set Transfer length
	move.w	#$9400, (a5)

	move.w	#$8114, d6		;VDP commands to turn screen on and off during HBlank
	;swap d6
	;swap d5
	;move.w d5, d6
	;swap d5
	;move.w d5, d7
	;swap d7
	move.w	#$8174, d7
	if USE_HINT
		move.w	d7, (a5)
	endif
	rte

LoadSpritePal:
	move.l	#$C0200000, (a5)
	moveq	#$F, d0
	lea	SpriteData, a0
PalLoop:
	move.w	(a0)+, (a4)
	dbra	d0, PalLoop
	rts

Player1Vint:
	move.b	(ButtonState).w, d2
	move.b	(ButtonStateNew).w, d3

	moveq	#0, d0
	move.w	d0, d1

	btst	#5, d2
	bne	ScrollRight

	btst	#7, d2
	bne	ScrollLeft

	btst	#4, d3
	bne	IncrementFrame


	btst	#6, d3
	bne	DecrementFrame

	btst	#2, d2
	beq	PlayerShipNotLeft
	subq	#1, d0
PlayerShipNotLeft:

	btst	#3, d2
	beq	PlayerShipNotRight
	addq	#1, d0
PlayerShipNotRight:

	btst	#0, d2
	beq	PlayerShipNotDown
	subq	#1, d1
PlayerShipNotDown:

	btst	#1, d2
	beq	PlayerShipNotUp
	addq	#1, d1
PlayerShipNotUp:

	bsr	MoveBigSprite

	rts
IncrementFrame:
	move.w	(PlayerShipFrame), d3
	addq	#1, d3
	move.w	d3, (PlayerShipFrame)
	bsr	ChangeFrameBigSprite

	rts

DecrementFrame:

	move.w	(PlayerShipFrame), d3
	subq	#1, d3
	move.w	d3, (PlayerShipFrame)
	bsr	ChangeFrameBigSprite

	rts

ScrollRight:
	move.w	(ScrollValue), d0
	subq	#1, d0
	move.l	#$7C000003, (a5)	;setup writes to HScroll Table FC00
	move.w	d0, (a4)
	move.w	d0, (a4)
	move.w	d0, (ScrollValue)

	rts

ScrollLeft:
	move.w	(ScrollValue), d0
	addq	#1, d0
	move.l	#$7C000003, (a5)	;setup writes to HScroll Table FC00
	move.w	d0, (a4)
	move.w	d0, (a4)
	move.w	d0, (ScrollValue)

	rts

	include	sprites.s68

PlayerShipFrame:
	dc.w 	0


ScrollValue:
	dc.w	0

ReadPad:
	move.b	#$FF, $a10003	;set TH for controller A
	move.b	$a10003, d0	;CBRLUD
	andi.b	#$3F, d0
	move.b	#0, $a10003
	move.b	$a10003, d1	;SA00UD
	andi.b	#$30, d1
	lsl.b	#2, d1
	or.b	d1, d0		;SACBRLUD
	not.b	d0
	move.b	(ButtonState).w, d1
	eor.b	d0, d1
	and.b	d0, d1
	move.b	d0, (ButtonState).w
	move.b	d1, (ButtonStateNew).w

	rts


SpriteData:
	incbin	bultest.bin
BgData:
	incbin  logo.bin