Nintendo DMG-01 - Game Boy Console Manual page 24

2.8.1. Tiles
WX may be changed during a scan line interrupt (to
either cause a graphic distortion effect or to disable
the window (WX>166) ) but changes to WY are not
dynamic and won't be noticed until the next screen
redraw.
The tile images are stored in the Tile Pattern
Tables. Each 8x8 image occupies 16 bytes, where each 2
bytes represent a line:
Tile:
.33333..
22...22.
11...11.
2222222. <-- digits
33...33.
22...22.
11...11.
........
As it was said before, there are two Tile Pattern
Tables at $8000-8FFF and at $8800-97FF. The first one
can be used for sprites, the background, and the
window display. Its tiles are numbered from 0 to 255.
The second table can be used for the background and
the window display and its tiles are numbered from
-128 to 127.
Page 24
represent
color
numbers
Game Boy
.33333.. -> 01111100 -> $7C
22...22. -> 00000000 -> $00
11...11. -> 11000110 -> $C6
2222222. -> 00000000 -> $00
33...33. -> 11000110 -> $C6
22...22. -> 00000000 -> $00
11...11. -> 11000110 -> $C6
........ -> 00000000 -> $00
TM
CPU Manual
Image:
01111100 -> $7C
11000110 -> $C6
00000000 -> $00
11111110 -> $FE
11000110 -> $C6
11000110 -> $C6
00000000 -> $00
00000000 -> $00
V 1.01