from Hacker News

I built my own Sega Genesis (Mega Drive) hardware dev kit from scratch

by regus on 1/21/22, 5:35 PM with 38 comments

  • by djmips on 1/21/22, 8:05 PM

    This is pretty similar to hardware made by Radical Software and Accolade for professional development back in the day. Also the EA dev hardware was similar but more advanced since it contained additional hardware for capturing the bus like a logic analyzer might. For the Accolade version it was very similar to this design. I worked on the debugger and it was a lot of fun. At the time we used the Lattice C compiler and I supported C source level debugging including watches that could use a C like parser.

  • by codazoda on 1/21/22, 7:59 PM

    I never really dared to dig into electronics like this. I had a nack for breaking things when I did.

    As an example, I purchased a Pentium machine back in the day. I had a feeling it was running too hot (or maybe I was trying to over-clock, I don't recall). But I decided to build a simple PCI card. So simple, in fact, that it just had a 12v case fan on it. I wired up the +12v pin and the ground pin to the 12v +/- of the fan. Then I plugged the PCI board into the PC. It worked! Except, it was now the only thing in the PC that worked.

    After removing it, the machine no longer worked. I returned it to the shop I purchased it from and they informed me that I must have had a surge. Everything was destroyed. The CPU, the RAM, the Video card, it was all gone.

  • by klodolph on 1/21/22, 10:14 PM

    Fantastic stuff!

    There are plenty of modern flashcarts around for various systems, but most of them are designed to let you load up a bunch of (often pirated) games onto an SD card and play them, and they're not very good for development. Nobody wants to build their ROM image, copy it to an SD card, swap SD cards around, and then reboot the system. (Plenty of people do that, it just sucks.)

    It goes to show that making your own cartridge for development is not as hard as you might expect.

    There are some high-end cartridges out there that let you do everything, with both SD cards and USB ports, but it's less common to see pure development cartridges, which could be made much more cheaply.

  • by hnthrowaway0315 on 1/21/22, 7:27 PM

    Laughing out loud, cheering and clapping my hands when seeing lines such as "As I was on a very tight budget, I decided to build my own. How hard could that be?".

    I wish I had that intuition and courage to build my own birdfeeder back in the day. And of course the author managed to do much cooler things.

  • by kingcharles on 1/21/22, 6:56 PM

    Contemporary with the console, the two kits I had for development were SN System's PsyQ, and the one you could buy at a decently stocked video games store was the Super Magic Drive which used floppies.

    https://twitter.com/bigevilboss/status/1142031487317020672

    https://segaretro.org/Super_Magic_Drive

  • by jdmoreira on 1/21/22, 9:57 PM

    I feel like this would be an inferior development experience in 2022 compared to this approach: https://hackaday.io/project/1507-usb-megadrive-devkit

    Which is an fpga in the cartridge that also serves as a gdb stub over serial. You can debug with gdb directly on the hardware.

  • by tsmarsh on 1/21/22, 6:21 PM

    I bought Ben Eater's Motorola kit and was overwhelmed, I have a whole new respect for folks that can do this.

  • by londondev45 on 1/21/22, 7:40 PM

    A message of appreciation, you sound very cool. I'd love to have seen this when I was a young sega mega drive obsessive

  • by bluedino on 1/21/22, 7:11 PM

    I would love to read this kind of article along with all the drawings and pictures of a similar kit for the NES, from the 1980's

    A lot of those early programmers knew electronics they just built their own stuff. Crazy compared to your average developer now. A lot of guys had to build their own terminals/keyboard etc back then (especially the 70's computer clubs). At some point the hardware and software kind of split up (lucky for us that didn't have any real hardware knowledge)

  • by rightbyte on 1/21/22, 9:43 PM

    Heh ...

        ut: 
      *wait for datapacket to be stored att $FF0000
     lea $ff0000,a5
    I like how he slips in three Swedish spelling "friend words" there.

    For some reason I have always found a relief in programming and mixing in my native tongue randomly. Like, it gives a playlike non tryhard touch to it. And the flow is nicer.

  • by rahen on 1/21/22, 9:44 PM

    It's great to see some new projects being wire wrapped. It's becoming some kind of lost art nowadays.

  • by Nexxxeh on 1/21/22, 6:07 PM

    Really cool read. Am I right in thinking it works like a flash cart, but with volatile memory?

  • by brokenmachine on 1/25/22, 4:35 AM

    Awesome stuff, I love reading about DIY hackery like this.

  • by nsxwolf on 1/21/22, 7:10 PM

    What's the sponge for?