The current URL is datacrystal.tcrf.net.
Strider (Genesis)/Notes
These are notes about gfx ressources. Work in progress...
The vocabulary used in these notes follows Charles McDonalds' document [genvdp.txt], easily available. Offsets refer to american version.
Palettes
Palettes are uncompressed. Most of them are stored from 0x22f08 to 0x23988.
Levels Maps
Levels maps are split in 256x256 submaps. Each submap is made of 16x16 tiles. Each tile is made of 2x2 patterns (a pattern is a 8x8 pixels stored in VRAM).
Due to the size of the map, there's always 2 set of submaps in RAM, one at 0xff0000, the other at 0xff3000. When the submap at 0xff3000 is displayed, the next submap is loaded at 0xff000, and vice-versa. The submap stored in 0xff3000 is refered by tiles id >= 0x80.
For example, the 1st level map is (ignoring 00 and 80's, that are blank submaps) :
02 03
86 88 01 04 05 06
85 86 88 8a 8c 83 85 87 89 05 01 81 83 85 87
82 84 87 89 8b 8d 82 84 04 06 02 82 84 86 88
01 02 03 04 05 06 07 81 83 8e 01 04 06
02 03 05
is actually made of 8 sets of submaps, denoted by letters below :
E02 E03
D86 D88 E01 E04 E05 E06
B85 B86 B88 B8a B8c D83 D85 D87 D89 G05 G01 H81 H83 H85 H87
B82 B84 B87 B89 B8b B8d D82 D84 G04 G06 G02 H82 H84 H86 H88
A01 A02 A03 A04 A05 A06 A07 B81 B83 B8e C01 C04 C06
C02 C03 C05
(the F set is loaded in the same location as G when entering a dome).