The M26C256B chip on my card is really cool looking. It has a see through window on it. I am guessing its the main chip or something to be pimped in such a way!
Nope that is an EPROM. The see through windwo is for eraseing it's content by UV-light. Better cover it up becauss normal daylight contains a potion of UV-light as well. So over a longer time the programming of the EPROM could be damaged.