snes background modes — free browser tool | fatcousin

home

snes ppu background mode reference · modes 0–7 · layer bpp colors tile size · offset-per-tile · mode 7 affine · priority order · key registers · runs locally

mode selector

all modes overview

modelayersBG1BG2BG3BG4OPTnote

042bpp2bpp2bpp2bpp—Rarely used

134bpp4bpp2bpp——Most commonly used mode in SNES games

224bpp4bppOPT—yesParallax scrolling effects per-tile column

328bpp4bpp———Detailed backgrounds with 256 colors

428bpp2bppOPT—yesUsed when you need 256-color BG with offset-per-tile parallax

524bpp2bpp———High-res text, detailed UI

614bpp2bpp——yesHigh-res with parallax

7 ★08bpp————Mode 7 — the SNES signature effect

sprite + bg priority order (mode 1, typical)

1Sprites pri=3 (highest)

2BG1 hi / BG2 hi (mode-dependent)

3Sprites pri=2

4BG1 lo / BG2 lo

5Sprites pri=1

6BG3 hi / BG4 hi

7Sprites pri=0

8BG3 lo / BG4 lo (lowest)

key ppu registers

addrnamedescription

$2105BGMODEBG mode select (bits 2:0) + tile sizes (bits 4:7) + BG3 priority (bit 3)

$2107BG1SCBG1 tilemap base address (bits 7:2) + mirror (bits 1:0): 0=32×32, 1=64×32, 2=32×64, 3=64×64

$2108BG2SCBG2 tilemap base address + mirror

$2109BG3SCBG3 tilemap base address + mirror

$210ABG4SCBG4 tilemap base address + mirror

$210BBG12NBABG1 (bits 3:0) + BG2 (bits 7:4) character/tile data base address (×8192 bytes)

$210CBG34NBABG3 (bits 3:0) + BG4 (bits 7:4) character data base address

$210DBG1HOFSBG1 horizontal scroll (write twice, low then high 3 bits, M7X in mode 7)

$210EBG1VOFSBG1 vertical scroll (write twice)

$210FBG2HOFSBG2 horizontal scroll

$2110BG2VOFSBG2 vertical scroll

$2115VMAINVRAM address increment mode (direction + size)

$2116VMADDLVRAM address low byte

$2117VMADDHVRAM address high byte

$212CTMMain screen layer enable (bits: OBJ BG4 BG3 BG2 BG1)

$212DTSSub screen layer enable (for color math)

$2130CGWSELColor math control (direct color, add/sub, sub screen)

$2131CGADSUBColor math layer select (which layers participate in blending)