Jonny_B Posted February 17, 2005 Share Posted February 17, 2005 While as Genesis controllers are compatable with most 2600 games, if you try to play a 7800 game, it will freeze, as if it were stuck in reset mode. I would like to modify one of my Genesis controllers to be compatable with 7800 games. I assume that it would mean removing and/or switching a few wires around. My bro is an expert at fixing and modifying stuff, but he would need a schematic to do it. Is there a link buried in these archives that leads to a schematic for a modified Genesis controller, or does somebody already know how, and would like to share some info? Anything would be appreciated, because I feel the 7800 controllers are a bit too awkward and tend to break easily if overused. Quote Link to comment Share on other sites More sharing options...
EricBall Posted February 17, 2005 Share Posted February 17, 2005 Hmm, I found two websites with Genesis controller info: http://www.hardwarebook.net/connector/user...controller.html http://users.erols.com/tiltonj/games/tech/smscont.html Then there's the A7800 FAQ for the 7800 controller: http://www.atariage.com/7800/faq/index.htm...mID=7800#cat2_9 pin # 7800 control 1 Up 2 Down 3 Left 4 Right 5 Button (R)ight (-) 6 Both buttons (+) 7 unused (+5v) 8 Ground(-) 9 Button (L)eft (-) Genesis 1 North 2 South 3 West or SEL mirror 4 East or SEL mirror 5 +5VDC Supply 6 A or B 7 SEL 8 GND 9 Start or C So first A7800 pin 7 has to be connected to Genesis pin 7 & 5. That will power up the 74HC157 and select normal (needed for proper left/right). Unfortunately, there's no way to make it a two button controller without rewiring the internals. You may also want to leave A7800 pins 5 & 9 unconnected. Quote Link to comment Share on other sites More sharing options...
EricBall Posted February 17, 2005 Share Posted February 17, 2005 Whoops, made a mistake about how SEL works. Hmm... Genesis 1 North 2 South 3 West or SEL mirror 4 East or SEL mirror 5 +5VDC Supply 6 B or A 7 SEL 8 GND 9 C or Start So first A7800 pin 7 has to be connected to Genesis pin 7 & 5. That will power up the 74HC157 and select normal (needed for proper left/right). Okay, now let me figure out how to connect B/C as left/right fire. Quote Link to comment Share on other sites More sharing options...
bjk7382 Posted February 17, 2005 Share Posted February 17, 2005 Looks like the nes mod would be easier than figuring all that out. http://www.geocities.com/gjp57/nes-7800.txt Quote Link to comment Share on other sites More sharing options...
+Mitch Posted February 17, 2005 Share Posted February 17, 2005 Or try here. Mitch Quote Link to comment Share on other sites More sharing options...
EricBall Posted February 17, 2005 Share Posted February 17, 2005 Nope, it doesn't appear to be possible to connect B/C as left/right. On the Genesys B/C connect pins 6&9 to 8 (common ground) and I can't match this to the 7800 fire button circuit without rewiring the internals. So connect 6 through and B becomes the common fire button & leave 9 unconnected so pressing C won't mess things up. Pins 1-4 & 8 are connected straight through. An SMS controller should work without modification, although button 2 won't work right. Quote Link to comment Share on other sites More sharing options...
Jonny_B Posted February 18, 2005 Author Share Posted February 18, 2005 Thanks for the help. Sega Master Systems are pretty rare where I live, nevermind the accessories. I'll print this stuff and give it to my bro to figure out. If a Genesis controller doesn't work, I'll try an NES controller. I've got plenty of those in storage. Quote Link to comment Share on other sites More sharing options...
Songbird Posted February 18, 2005 Share Posted February 18, 2005 I have no idea where this can be found online, but about 8 years ago I built an external project box based on some internet info which had Dsub9 connectors on each side. I plugged in a non-modded Genesis controller on one side, and a simple 9-pin extender cable on the other side, and voila! I had two-button support on the 7800. It worked great except my soldering wasn't up to par and the board got damaged eventually... Anyway, I guess the point is you should be able to build an external box so that any unmodified Genesis controller would work properly on the 7800. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted February 18, 2005 Share Posted February 18, 2005 I have no idea where this can be found online, but about 8 years ago I built an external project box based on some internet info which had Dsub9 connectors on each side. I plugged in a non-modded Genesis controller on one side, and a simple 9-pin extender cable on the other side, and voila! I had two-button support on the 7800. It worked great except my soldering wasn't up to par and the board got damaged eventually... Anyway, I guess the point is you should be able to build an external box so that any unmodified Genesis controller would work properly on the 7800. Yep, see my link above. Mitch Quote Link to comment Share on other sites More sharing options...
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