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Trying to get VRAM DMA to work

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For tile map
This commit is contained in:
greg 2016-12-14 11:05:38 -08:00
parent 3ef2eee4b0
commit 23bdc734bb
1 changed files with 16 additions and 3 deletions
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19
test_gfx.asm
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@ -26,7 +26,7 @@ VBlank:
Video_Port_Control
ldx #DEST
stx $2116 ; $2116/2117 is 2byte address for VRAM upload/download. most significant bit must be 0
stx $2116 ; $2116/2117 is 2byte address for VRAM upload/download. most significant bit must be 0
lda #:SOURCE ; source bank
ldx #SOURCE ; source offset
@ -64,7 +64,6 @@ Start:
; size (last argument) depends on color mode
; location is beginning of VRAM
Load_Block_to_VRAM Tiles, $0000, (8*2*2),
; put character data at VRAM $0000, tile data at $0400
lda #$04
@ -72,10 +71,15 @@ Start:
lda #$00
sta $210b ; BG1 character location ($1000 word intervals - can't go over $8000 b/c size of VRAM)
stz $1337
; main screen designation
lda #%00000001
sta $212c ; enable bkg 1,
; Load_Block_to_VRAM TileMap, $0400, 16
Load_Block_to_VRAM Tiles, $0000, (8*2*2),
ldx #$0400 ; load $0400 (VRAM address of tile data)
TileLoadLoop:
@ -95,7 +99,6 @@ TileLoadLoop:
cpx #$0780 ; $400 - $780 seems to be limit of snes screen tile memory
bne TileLoadLoop
lda #%10000001 ; enable NMI and joypads
sta $4200
@ -156,4 +159,14 @@ Tiles:
.db %00111100
.db %00111100
TileMap:
.db $00, $01
.db $00, $01
.db $00, $01
.db $00, $01
.db $00, $01
.db $00, $01
.db $00, $01
.db $00, $01
.ENDS