Many Atari documents and projects have been lost to the ages. Thankfully historians, former employees, and hobbyists are working to find and preserve as much as they can. The engineering schematics for the Atari 7800 have been released to the public for the first time. The documents were originally found in a dumpster, but have been preserved

Source: Hot Hardware – Rare Atari Schematics Have Been Discovered And Released To The Wild