Problems with higher resolution of graphics in older games.

[Xela]

Just like in the title.

I am dealing with few older titles which were produced with rather crude graphics. I am trying to increase the resolution by bumping the resolution of the textures. But I am getting very weird results. The textures are 8 bit grayscale with palette (actually several palettes to simulate different time of day). After they are bumped the game displays them kind of scrambled and distorted.

Here is one example:
http://www.simhq.com/simhq3/sims/boards ... 105#000007

Any help, or link to some articles on the web would be appreciated.

[Xela]

Maybe this is wrong lead, but for now I am thinking that graphics I am trying to up in size are loaded and reside in the the memory cache. Graphic memory cache is something hardcoded right? And is fast to access and therefore to display.

Any information I can find when how and when, how and why the designers were deciding to use this approach vs. regular textures?