Ever since I stumbled upon the GenMDM project I wanted to try it but it seemed impossible to get my hands on one. So a few years ago I tried to clone one. By just looking at all the images I could find I was able to reconstruct the connections between the Teensy and the DB9 connector. It was surprisingly easy!
what you will need:
- A working Sega Megadrive (Genesis). I use a Megadrive 1 because it has a convenient headphone output.
- Teensy (ATmega32u4 USB dev board) 2.0
- An old controller to use the cable or DB9 connector (you’ll have to cut the right corner for it to fit).
- A small PCB is nice but you could easily just solder directly to the Teensy
- GenMDM Firmware and GenMDM ROM
- An EpRom burner to create the cartridge, or an Everdrive.
So how to connect the teensy to your MegaDrive or Genesis? This is so easy I didn’t even bother to draw a schematic. See fig.1 for the connections.
GenMDM is now for sale at catscullelectronics. This is the place where you can download the ROM. I will not provide it directly just use your Google-fu! Use this rom to create your own cartridge with an eprom burner (I really need to do a write up on this) or if you’re lazy put it on your Everdrive.
The firmware you need to flash your teensy with is still available at little-scale-blog (the original creator of GenMDM). Again use your Google-fu! Now flash the firmware into the teensy and you are ready to go! *edit* since these files are no longer available, here is a link to the wayback machine
Use the second port to plugin your clone and turn on your Sega. You should hear a sound there will be no output to the screen. Then connect the usb to your computer, again you should hear a sound. Congratulations you now have a working connection between your computer and your Sega. 🍻
Hey man! thanks for posting this, I was wondering, since the teensy 2.0 is discontinued, are there alternatives? or the firmware is only compatible with that board?
Hey there. I read your article which is great but I’m new to this microcontroller stuff. Could I use any Arduino or must it have the exact same chip? Is it just like a PC where any chip will run windows or does the chip affect the pins? Basically I have a few Uno’s here and might just use one if possible. I appreciate your help.
To the vandoeselaar.com owner, Your posts are always well-supported by research and data.