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CoCo Digital Joystick Adapter

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    CoCo Digital Joystick Adapter

    I am new here and this may very well be posted in the wrong forum area .. moderators, please relocate as needed.

    Hello to all the Vintage Computing users here .. please forgive any opinions expressed here, as I am a long time Commodore enthusiast, and this is certainly not new news to the Tandy enthusiasts. The following is an excerpt from another forum where I am also polling interest.

    In 2007, a Donkey Kong emulator was released for the Tandy Color Computer 3, which otherwise is a rather unsensational micro. However, the Donkey Kong emulator for the CoCo 3 is a remarkable port of the arcade machine. No other release of Donkey Kong for any other micro nor console was ever done this well, short of actual MAME emulation.

    I saw this recently running on a CoCo at the MidWest Vintage Computer Festival and was blown away. The sound, color, and game play were spot on. The remixed version is even more amazing and is really tough, where I've since been playing it via the VCC emulator. I'm considering getting a CoCo 3 just for the DK ports alone, along with the CoCo SDC cart, which is still available.

    What's not readily available however is an Atari 9 Pin joystick adapter. So I drafted a tiny one up last night that should fit in a 9 pin D-Sub shell. It adapts an Atari style D-Sub 9 connector on one end to a male Din 6 on the other end to plug in to the CoCo 3. I don't have a CoCo 3 yet, but I'm considering having these 9 Pin adapter PCB's printed to justify the acquisition. I can then use a TAC 2 or any other Atari type joystick with the CoCo 3, which is really a prerequisite, as the native Tandy sticks are analog.

    The circuit is based on the one posted on the CoCo wiki. If anyone would like to crowd fund this with me, I can compile some kits and even solder up some full adapters if there's interest. I'm thinking $6 for a kit or $12 for a built adapter plus shipping .. the usual $5 domestic or $10 overseas. With 10 confirmed pledges, I can submit the PCB for fabrication.

    I'll be doing a one time run of PCB's and assembly, and then that will be all. I don't require any payment upfront, only a commitment to follow through on any interest expressed by the time the PCB order is placed. Payment would be via paypal and shipping is world wide. This is a public service, group funded offer and I'll combine interest here with the other forum posts. I anticipate having the PCB's printed next week and should have them back and shipping kits or full adapters by mid October. Updates will be made here in this thread.

    All three models of the Tandy CoCo use the same port and controllers, as does the Tandy 1000, so this project has broader appeal than just the CoCo 3. I have long been wanting such a solution for my Tandy 1000s for years.

    Two questions before I say "I pledge". First, will it work with a Sega Genesis controller? Unlike the Atari and Sega Master System digital controllers, the Genesis controller has a multiplexer chip for its switches.

    Second, will we need to solder DE-9 and DIN-6 connectors to the board?
    My Retro Computing and Vintage Gaming Blog :


      Originally posted by sys64738 View Post
      In 2007, a Donkey Kong emulator was released for the Tandy Color Computer 3, which otherwise is a rather unsensational micro.
      Wow. Good thing you stated that you're new here!

      There are plenty of folks (including me) who will dispute your claim. I believe this past spring the *24th* annual Last CoCo Fest was held in Illinois. The fanatics are keeping the machine alive as avidly as any other. The CoCo remains an amazingly capable platform - as is evidenced by the DK remix that you're talking about.

      Welcome! And, thanks for your contributions already coming in.



        smp .. indeed, my coco experience is limited to what I've checked out so far via VCC and some online archives I've found. The DK ports are fine examples of what this micro is truly capable of. I look forward to further exploring all I can find for the coco.

        GH .. I do not own a coco yet, so the circuit is drafted directly from the one in the coco wiki ..

        It's a simple circuit, and I checked an older thread here using the search engine and found someone else had tried one of the two circuits, which are both near the same, and it worked for him. It's essentially translating the 4 directions to an X and y value used by the coco via the 4066 mux IC. I don't pretend to understand how it works exactly, so the buy in is on faith that the circuit works. From my linked draft picture, it should take one only a few minutes to verfiy I routed the traces correctly. So the risk is on faith of the original circuit author, where you can follw the link in the circuit diagram to see his other work. I personally have a lot of faith that it will work.

        I'm offering to provide kits that one would solder up, or fully built adapters. Kits would include the D-Sub (DB9) housing either full metal or metalized, a metal male DIN-6 connector, a male DB9 connector, the 0805 SMT resistors, the SMT 4066, and the PCB .. cable may or may not be included .. not sure on that yet. Fully assembled will require no soldering, no assembly, just plug it in to the coco and your 9 pin digital stick in to the adapter. The board should fit inside the DB9 housing .. this is an estimation, as the PCB is tiny at 14mm long and 16.5mm wide. If it does,the adapter will be fully enclosed and about 4 inches long, a DB9 on one end and a DIN6 on the other.

        This is what I'd be using for the DIN-6 ..

        I'm considering using these for the D-Sub ..

        As far as compatibility with Sega controllers, only if they are simple on/off digital controllers using the Atari joystick pinout. I intend to use either a TAC 2 or an Epyx 500XJ joystick.

        So for me to do the PCB run, I'm looking for buy in on faith of the wiki circuit posted. I will deliver kits or fully built adapters, based on the original circuit translated to the PCB I've drafted. If it works, which it should, it will be a high quailty compact, durable adapter.



          I think the circuit is easy enough to understand. The fire buttons are past straight through, they are digital inputs that pass the GND signal through when pressed. Two of the directionals, Left and Down, when pressed, indicate a pure +5v sent (minimal voltage division provided by the joystick). The other two directionals, Right and Up, when passed, indicate a pure GND send (maximum voltage division provided by the stick). Each of the A-X-Y pins acts as a switch and each directional is tied to a switch. The 10K resistors act as pull ups to +5v because the 4066 inputs are active high. When A1 is active (Left directional is pressed), it sends the input X1 to the output Y1 and so on for the other three inputs.

          I would pledge for one, maybe two.
          Last edited by Great Hierophant; September 14, 2015, 05:13 PM.
          My Retro Computing and Vintage Gaming Blog :


            I'd be interested in one. I have one of your Telengard DDI carts, it's great!
            Crazy for 8-bits!
            Mame cab:


              Why not release it on OSHPark as a public project so others could make more after your only run is gone?
              -----[ Al ]-----

              3 - TRS-80 Model I, TRS-80 Model 4D, LNW-80 Model I, Coco, 3 - Coco 2, Coco 3, 2 - Tano Dragon 64, C64, C64c, C128, 2 - Atari 800XL,
              Atari 520-ST, Atari Mega-2 ST, Amiga 1000, TS-1000, TS-2068, ZX-Spectrum, IBM 5150, 2 - Apple ][gs, Laser 128, and a butt load of Macs and Intel PCs.


                Put me down for an assembled adapter please.


                - Ed


                  I would also like an assembled adapter. Thanks!


                    If this supports Tandy 1000 I'm interested in an assembled adaptor also. Thanks


                      I would like an assembled adapter please!



                        Please add me for an assembled adapter as well.

                        Thank you!


                          Hello. Your project is very interesting.
                          Please, put me down for an assembled adapter.

                          Thank you,


                            put me down for an assembled adapter


                              Add me for an assembled adapter