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Sega Genesis controller


Opry99er
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Can someone link me to pinouts on how to set up a Genesis controller as a direct plug-in joystick replacement for the TI?

 

I do not want to use an adapter.

 

 

Thanks!

 

I would be limited of course since the TI only uses one fire button.

 

The pinouts for the Sega Genesis controller are

 

HERE

 

You can map the pins on the 99/4A joystick from

 

HERE

 

Should be able to wire the pins up by matching the correct ones on each side.

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I think if you try to do this on an unmodified Genesis controller you'll run into the problem that only Up and Down will work. The rest of the switches go through the mux chip in the controller and that won't work without 5v power on pin 5. You can modify the controller to bypass the chip and connect the switches directly instead. http://smalltimer.net/dlormand/segactrl.htmlhas instructions for doing this to produce an Atari-style pinout. You could follow those instructions and then try switching the pinout on the cable around to match the TI-99.

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You could run all the extra switches to player 2's common...

 

directions, player 1 common and direction.

button A - player 1 common, & fire.

button B - player 2 common & fire.

button C - player 2 common & up

start - player 2 common & right

 

Now you can read all those buttons with TI BASIC if you like, without conflict.

 

-M@

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Thanks for the links, guys. :)

 

The one specifically for the Genesis to TI conversion was one I found on a quick Google search prior to posting this thread.

 

It lays out the way to turn the Genesis into an Atari-style controller. It is great, and I only need the one button.

 

Thing is, I was hoping to go straight in with no Atari adapter. I will study more to determine whether this is possible.

 

 

Again, thank you for your help!!!

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The Genesis controller is already an Atari-style controller with zero conversion needed. Sega was smart enough to make them plug-in compatible.

 

Since the open market has so many Genesis variations (Atari options, Standard Genesis, Sports Trackball, Arcade Multi) and they all work with a cheap $10 Genesis-to-TI converter dongle, why mess with the pin outs?

 

Why not just get the TI-to-Atari pin out dongle and give yourself tons of options?

 

 

Sent from my iPhone using Tapatalk

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The Genesis controller is already an Atari-style controller with zero conversion needed. Sega was smart enough to make them plug-in compatible.

 

Since the open market has so many Genesis variations (Atari options, Standard Genesis, Sports Trackball, Arcade Multi) and they all work with a cheap $10 TI-to-Atari converter dongle, why mess with the pin outs?

 

Why not just get the TI-to-Atari pin out dongle and give yourself tons of options?

 

 

Sent from my iPhone using Tapatalk

 

Sent from my iPhone using Tapatalk

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I wonder if they just need the +5V power that is normally on an Atari joystick port? That's why an Atari Trackball doesn't work on a TI either--give it power on that pin from an external source and see what happens. . .

 

i can test this for you.. i have some controllers will have to dig them out

 

Greg

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Genesis controllers have a parallel to serial shift register chip inside that bring all the buttons encoded back as a serial signal, except the dpad.

 

For my TI and Tomy Tutor, I remove the chip and just use the switches.

 

The chip is surface mount so I do things like take a dremel and grind all the traces I don't want.

 

For best results on a 4A, use the controller's screwdriver interface.

 

Or, use a little PIC chip to talk to the sega device and pretend to be the TI device.

 

-M@

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  • 3 weeks later...

Genesis controllers have a parallel to serial shift register chip inside that bring all the buttons encoded back as a serial signal, except the dpad.

 

For my TI and Tomy Tutor, I remove the chip and just use the switches.

 

The chip is surface mount so I do things like take a dremel and grind all the traces I don't want.

 

For best results on a 4A, use the controller's screwdriver interface.

 

Or, use a little PIC chip to talk to the sega device and pretend to be the TI device.

 

-M@

 

That's not quite correct--the NES and SNES have a shift register. The Genesis has a quad 1-of-2 data selector, a 74LS157. You supply 5v on pin 5 to this chip and keep pin 7 high if you want to read the four directions and the B and C buttons. Drop pin 7 and you can read Start and A.

 

This is NOT actually Atari-compatible. Atari provides +5v on pin 7. Pin 5 is one of the paddle inputs, which the electronics nerds in the group can tell you is not harmful to the RC charge timer used to read the pot on the Atari. The reason these work on the 2600 is because putting 5v on pin 7 inadvertently powers the TTL chip. The pot turned all the way to one side would do the same thing.

 

The console has NC joystick pins and any one of them could be wired for +5, but it would be a mod you'd have to consciously choose to make.

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Thanks! I was going off of how I understood (misunderstood) the joymega adapter for MSX to work.

 

Empirical testing of genesis controllers on a 4A with atari adapter looks like it works for a moment. Just a moment. The B button does not work, unless you are also pressing a direction. Don't mistake that for actually working, or those binites will kill you.

 

Now, there was tale long ago of someone here that developed a proper adapter? Anyone know what happened there?

 

I have looked at adding external power through an atari adapter, it functioned well enough to add the +5v and connect ground to the player1 common signal on the 4A. But that isn't actually the correct thing to do. Player 1 common on the TI isn't really ground, I don't believe, except when the Joystick is being scanned. And it doesn't work for 2 players, as you would be binding the commons together, and the 4A would not be able to tell the 2 players apart.

 

-M@

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The usual Atari adapter is all you need, if pin 7 has +5 on it.

 

I'm actually considering wiring up some NES controllers to work on the TI, Atari (SMS mode) and possibly switchable to Atari 7800 mode.

This messaging is what I'm trying to prevent. I believe it comes from a failure to understand that on a 4A there is no power or GND lines at the Joystick port. And 'the usual' atari adapter is a passive device, that does not bring power to the table for us 99ers.

 

-M@

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This messaging is what I'm trying to prevent. I believe it comes from a failure to understand that on a 4A there is no power or GND lines at the Joystick port. And 'the usual' atari adapter is a passive device, that does not bring power to the table for us 99ers.

 

-M@

 

I realize the TI has not got +5 to the port. In fact I said so three messages above. If you add an external powersupply, it'd work. If you don't, it won't. That's why I'm planning to rewire some NES controllers as SMS controllers--those will.

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