Activision was the first third-party Atari 2600 developer, but they didn't have to reverse-engineer the system from scratch -- they were all defectors from Atar

Activision was the first third-party Atari 2600 developer, but they didn't have to reverse-engineer the system from scratch -- they were all defectors from Atari. They did invent plenty of nifty tricks, though. One podcast talks about Imagic, another VCS third-party developer: One guy, Bruce Pederson, was amazing. Without any documentation whatsoever, he attached an in-circuit emulator to a VCS and reversed the entire video architecture - including the special registers that doubled or tripled the sprites along with the requisite code timing issues. Took him two days to do it. Parker Brothers used existing carts to inform their efforts: The 2600’s zany graphics chip was the key thing there. My first contribution was to write a disassembler for already-published cartridges. When analysis of the circuitry presented ideas for how the sprites and background worked, I wrote small test programs on the 2600 to verify our assumptions. With these combined efforts, we figured out how everything worked in a few months. [1] http://2600gamebygamepodcast.blogspot.com/2014/02/q-with-imagics-michael-greene.html http://2600gamebygamepodcast.blogspot.com/2014/02/q-with-ima... [2] http://www.retrogamer.net/retro_games80/the-making-of-star-wars-the-empire-strikes-back/ http://www.retrogamer.net/retro_games80/the-making-of-star-w...