7800 Controllers on Genesis

[doug0909]

Questions before I try this on real hardware...

 

1. Can you use a real (2-button) Atari 7800 Controller on a genesis? If so, how will the buttons map?

 

2. Can I use a colecovision 9-pin splitter (the type that let you plug a colecovision stick and a 2600 joystick into one colecovision joystick port simultaneously for access to the colecovision keypad while using 2600 sticks) in order to plug a 7800 and genesis stick into the genesis port at the same time (for access to start, mode, 3rd button)?

 

Thanks... Really getting into Space Invaders 91!

[doug0909]

oh well... maybe I should post this in another forum topic?

[RetroLucky]

I tried this once as a kid and it didn't work out

[doug0909]

I tried this once as a kid and it didn't work out

 

Did anything explode? Because if nothing exploded, I should probably try it.

[RetroLucky]

 

Did anything explode? Because if nothing exploded, I should probably try it.

Nah, nothing bad happened. It didn't map out however

 

I think nothing worked except pressing down registered as A. I do remember I tested this with road rash and a standard 7800 controller, not the more nes looking controller

[doug0909]

Oh I thought with 2600 controllers it all maps and the button is "B". I thought this would just add A. Or C. Or nothing.

[RetroLucky]

It could be a simple pin swapping adapter solution, but as-is it wasn't plug and play

 

I was about 10 years old when I did it back in 96, so it's nothing I would have spent much time exploring

[BassGuitari]

oh well... maybe I should post this in another forum topic?

Patience, grasshopper.

[+wongojack]

The 7800 controller is just a simple Hi/Lo signal design with a couple pull-up resistors on the buttons. It definitely won't break anything, but it is possible that neither button will work.

 

I've built my own 7800 controller, and I've looked at the adapter that goes the other direction (Sega on 7800), but solutions were so available that I never built one myself. IIRC, if you plug a sega controller into a 7800 without an adapter the directions work and one of the buttons works fine, but the "other" button is continually pressed. So if you were playing Xevious, I seem to remember that without an adapter I could control the ship and fire, but my ship was just continually bombing (button 2).

 

What does all this mean? My best guess is that if you could figure out a way to press START (with a Y cable as you suggest) then the 7800 controller would likely let you control direction and possibly one button. I'm doubtful that it would allow you to control 2 buttons, and I don't remember which buttons they would be if they did work. It would be easy enough to verify from the pinouts, but I think B would have a chance of working and C would be the second button on the 7800 controller that would not work.

 

As for the Y cable, if you bought that from Nurmix here on the boards then I believe he connected all 9 wires straight through to all 3 ports on that thing. It isn't a "Coleco" Y cable as much as it is just a straight through DB9 Y cable. It should work just fine. The only thing that would prevent such a cable from working would be if it were designed to actually re-map the wires instead of send them straight through (or if it just didn't connect some wires at all). That was not the purpose of the Y cables that Nurmix built for the Coleco (unless I am totally mis-remembering that design). It definitely won't hurt anything to connect it and try.

[doug0909]

Thanks!

 

The 7800 controller is just a simple Hi/Lo signal design with a couple pull-up resistors on the buttons. It definitely won't break anything, but it is possible that neither button will work.

 

I've built my own 7800 controller, and I've looked at the adapter that goes the other direction (Sega on 7800), but solutions were so available that I never built one myself. IIRC, if you plug a sega controller into a 7800 without an adapter the directions work and one of the buttons works fine, but the "other" button is continually pressed. So if you were playing Xevious, I seem to remember that without an adapter I could control the ship and fire, but my ship was just continually bombing (button 2).

 

What does all this mean? My best guess is that if you could figure out a way to press START (with a Y cable as you suggest) then the 7800 controller would likely let you control direction and possibly one button. I'm doubtful that it would allow you to control 2 buttons, and I don't remember which buttons they would be if they did work. It would be easy enough to verify from the pinouts, but I think B would have a chance of working and C would be the second button on the 7800 controller that would not work.

 

As for the Y cable, if you bought that from Nurmix here on the boards then I believe he connected all 9 wires straight through to all 3 ports on that thing. It isn't a "Coleco" Y cable as much as it is just a straight through DB9 Y cable. It should work just fine. The only thing that would prevent such a cable from working would be if it were designed to actually re-map the wires instead of send them straight through. That was not the purpose of the Y cables that Nurmix built for the Coleco (unless I am totally mis-remembering that design). It definitely won't hurt anything to connect it and try.

 

I'm too old to remember for sure where I bought anything, but I think my Y cables are actually vintage, made for colecovision owners who wanted to use Atari sticks.