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Active: 23/09/2020
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About Version for Megadrive » Back to the Future Part III (USA) Low intensity colors

Low intensity colors are a bug in the actual cartridge of the game as documented. There is a patch in romhacking.net (https://www.romhacking.net/hacks/4792/ to fix it with this description about the bug:

Back to the Future: Part III, for Sega Genesis / Mega Drive, is a game that is
broken in a particularly weird way. Genesis games use a 9-bit palette, with 3
bits each for Red, Green, and Blue color intensity. These are stored in a 16
bit "word" (2 bytes) using the format:

0000bbb0 ggg0rrr0

Somewhere in the development process for this title, the programmers got things
mixed up, and mistakenly stored all palette data - and code to modify colors -
in the wrong format instead:

00000bbb 0ggg0rrr

In other words, all bits shifted right by one place. The result is that all
colors on screen are reduced to *half their intended intensity*, making the
game look dim, and with low contrast. How QA missed this is beyond me... I
guess their TVs were just turned up really, really bright.

In fact, there is one place in the game that DOES have the correct palette:
the SEGA logo that displays when the game is first turned on. It's likely the
logo, and the associated "color fade" code, was taken from SEGA documentation.

Edited by: admin on 27/07/2020 - 22:11

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