To be honest, I really wanted to like the Atari 7800 controller. It was shaped like a coffin and looked all space-age and stuff when it came out. But after 10 minutes of using it I knew it was just another SNAFU by Atari. While Europe and the rest of the world got the super cool Atari Joypads with the 7800 release, America had to deal with these horrible POS's.
So, what options do you have? You could try and hunt down an original Joypad on eBay or you can modify one of the other plentiful compatible controllers out there to work for you instead.
Natively the Sega MS controller will work flawlessly with the Atari 2600 but due to the two button design of the Atari 7800, the pinouts are not compatible with this Sega controller. By sacrificing... (and I use that word loosely) an extra 7800 joystick we can merge the two together and build a controller worthy of the Atari ProSystem greatness! Heat up the soldering iron and lets get to it!
Step 1: Whatcha will need....
1. A Sega Master System controller, both model 3020 and the 3060 "control stick" work just as well.
(I found one at a local used game shop for 3 bucks)
2. A crappy Atari 7800 controller.
(oh crap I have a lot of these bastards...)
3. A soldering iron and solder
4. A de-soldering tool or de-solder braid
5. A Phillips head screwdriver
6. A Pair of wire cutters
7. Bitter frustration and hatred of the damn Atari coffin controllers.
And as always...
8. Plenty of good cold beer...
......for this project we will be consuming some New Belgium: Fat Tire.