Eyecatcher

The eye-catcher animation coded in the BIOS comprises both sprites and FIX layer tiles. The graphics data for both must be provided in the cartridge sprite and FIX ROM images.

NEO-GEO LOGO
The revolving NEO.GEO graphic consists of sprites (bank specified by the word in the 68k program header address $115).

The palette is updated on-the-fly (from data stored in the BIOS (SP-S2) ROM @$C1F03E) to implement the fade effect.

MAX 330 MEGA
The "MAX 330 MEGA" & "PRO-GEAR SPEC" text as seen on smaller/early-release cartridges (eg. Puzzle De Pon) comprises FIX-layer tiles. The tiles used are defined in the BIOS (SP-S2) ROM @$C1F34A. Each line of text is itself two (2) FIX-layer tiles high, and is animated using a 'wipe in' effect from left-to-right to render each line in turn. These are the tiles used to display each line of text:

SNK LOGO
The SNK Logo consists of FIX-layer text which is actually rendered (invisible) at the start of the eye-catcher routine.

The copyright "(C)" symbol is a single tile (0x7B) written to VRAM adress 0x7469.

The logo tiles are palette #15, colour #5 which is initially BLACK (0x0000) and then faded-in through a cycle of progressively brighter blues to a final value of 0x306E.

PALETTE
Both the revolving logo and the FIX-layer text utilise palette #15.

Here is the *final* data written to palette #15:

CUSTOMISATION
It is possible, then, by replacing the FIX-layer tile data for the above tiles with alternate text/graphics to create a somewhat customised eye catcher without requiring a custom eye-catcher routine in the game cartridge itself.

The only caveat is that tile #0xFF is used in the "PRO-GEAR SPEC" display (see array data above) and is also used as the blank/space character for the entire screen. Thus this tile cannot be changed without replicating it over the entire FIX-layer background.