Sega Master System / Mark III / Game Gear
Sega8bit & SMS Power! 2013 Event - 10th August 11 weeks and 3 days from now
This page is incomplete.
For the SMS in mode 4, the displayed colours are updated immediately after a write to CRAM.
For the GG in SMS mode 4, the behaviour is the same as an SMS.
For the GG in GG mode, any writes to an even address will go to a latch, and CRAM is unchanged. Any subsequent write to an odd address (even a non-consecutive one) will write two bytes to CRAM to define a single palette entry:
These are the colours corresponding to the colour indices on an NTSC TMS9918a:
The SMS VDP converts the TMS9918a colours into approximate equivalents in the SMS's standard 64-colour palette.
The rightmost column is a comparison to the standard TMS9918a colours. As you can see, they are markedly different (generally, darker).
The Game Gear maps the TMS9918a colours to the corresponding palette indices. However, it does not set the palette, so they are all black (or possibly other values on a console with a BIOS). If a valid palette is written, games are playable; some pirate games were hacked to do this and there is a hacked Tototek menu available that does the same thing.