Fifty pages of complete engineering schematics for the Atari 7800 and its associated ICs have been released by Curt Vendel, the historian behind the Atari Museum History Project. The documents have circulated among private individuals for years, but this is the first time they have been publicly accessible.

The schematics essentially provide a blueprint that can be used to transcribe the 7800 into HDL (hardware description language) code for FPGA projects like MiSTer, although Curt notes that they contain a memory hole that will need to be addressed. The documents will be helpful to the team behind the Atari 2600 MiSTer core as well, since the 2600 and 7800 share a lot of hardware. HDL can be used to produce physical chips as well, meaning the same code used for an FPGA core could be used to produce new replacement chips or possibly even the entire 7800 PCB.

The schematics span 1983 thru August 1984 and cover the entire TIA-MARIA-STEPHANIE chip.

Curt retrieved the documents from a dumpster full of old Atari documents. Curt has shared a hoard of other Atari design documents on his site as well, any one of which could lead to exciting new cores to enjoy at home.

Big Announcement… I have just posted all of the sheets up for the TIA-MARIA-STEPHANIE chip. Now a work of caution, there is a memory hole error in these schematics, so if anyone plans to do some VHDL work please keep this in mind.https://t.co/3hMzMoyaRx — Atarimuseum.com (@atarimuseum) October 19, 2019

Source: http://www.atarimuseum.com/videogames/consoles/7800/7800menu/

Documents: http://www.atarimuseum.com/videogames/consoles/7800/tiamaria/tia-maria.pdf