These are schematics for the NES, a piece of a bygone era where a younger me decided to try to build a Nintendo Entertainment System, then build it into a portable machine, a la Benjamin Heckendorn's projects. The website offers some surprises on the first page: a custom-built and working Atari 2600 motherboard hand-wired (link here) and a fine review of a certain top-grossing film that closely mirrors our own.
Anyway, here are the NES schematics. The cover page (Page One) was omitted, and I did not scan these.
The site I found them at was here back in 2004, but I honestly don't know how long it will stay up. Consider this one a mirror.