A New Commodore C128 Cartridge

A new Commodore C128 cartridge in 2023?  That’s what [idun-projects] set out to do and, as you can see in the video below, did. I did the original C128 hardware design and worked with the amazing team that turned this home computer out in 1985. Honestly, I am amazed that any of them are still working 38 years later, let alone that someone is making new cartridges for it.

I also never thought I would hear about someone’s in-depth experience designing for the ‘128. The post takes us through [idun-project’s] decision to use the ‘128 and how modern expectations apply to all computers, even the old ones. Hot on the list was connectivity and reasonable storage (looking at you, floppy disks).

With newer expectations comes newer tools and, yes, operating systems.  The project draws inspiration from the ACE “Advanced Computer Environment” created by [Craig Bruce] in the 1990s, a mere 20 years ago.

Tackling 6502 assembler programming in the new environment, [idun-project] set about the goal of making the C128 talk to a Raspberry Pi without burdening the Pi down too much, hence a cartridge based on the Parallax Propeller 1. Even overclocked, though, it was a challenge to match the 6502 bus.

Frankly, when I hear about a piece of C128 hardware surfacing, I expect it to look more like the one [Drygol] restored. Of course, if you have the Propeller, you could just emulate the whole computer.


18 thoughts on “A New Commodore C128 Cartridge

  1. I’m as reluctant to admit this as anyone, but there is no part of the 1990’s that was just 20 years ago…

    This is an extremely impressive project, involving setting up a whole SBC as an interface between two other computers.

  2. If you thought new game for 40 years old computer was amazing, wait till you find Atari Age store! Mind blown!! New 2600, 5200, 7800, Lynx, and even Jaguar games along with Atari computers plus other 70s and 80s systems.

    Now if HaD can do an article on growing a money making tree so I can afford to buy all the new games…

    1. This isn’t just impressive because it’s a game for a ’40yr’ old computer, those are released all the time. This is more impressive because it’s released for a ’40yr’ old computer that was released at a time, where it didn’t really belong and didn’t see much love from DEV’s.

      There’s a distinct possibility that this might be, if not the first game cartridge for this system, only the second EVER!

  3. There’s an impressive tech demo of a cartridge someone made for the Commodore 64 that runs a fully 3D and smooth scrolling version of Doom. It is impressive, but it’s kind of a cheat. The full game runs entirely on the Raspberry Pi inside the cartridge and then the output screens are converted in real time to multicolor mode and made visible to the c64s video hardware. The project is called RAD. https://youtu.be/tG2TMkBB6JU

        1. I just found out about the Idun project from watching Adrian’s Digital Basement II. I love the idea plus that Bill Herd recognizes it, but I am troubled by a couple things.
          Z80 mode? I have NEVER used this CP/M part of my C128 but I always meant to.
          Propeller as the interface between C128 and Pi-Zero 2? Because as Bill points out, the Propeller by itself has several times the processing power of the Commodore.
          And it’s got the Pi, which can easily emulate a Mac SE if not an Amiga. Can these devices be harnessed somehow to make a better CMD SuperCPU? Probably not the way the cartridge circuit is done, but it would be a nice feature to have working on a future iteration (perhaps).
          I only recently realized who Gary Kildall was (from all the Computer Chronicles episodes). The guy behind CP/M!

      1. I haven’t checked it out, but supposedly there’s also a full 6510 emulation project that runs on the same hardware. In theory this could act as a superfast accelerator for the C64, similar to the old CMD SuperCPU that had a 20mhz 65816 and could run games for the old breadbox about 20 times faster. The RAD version would probably be able to go MUCH faster, possibly on the order of several hundred megahertz. I would love to see what demo and homebrew coders would do with a C64 running at, say, 200mhz.

  4. I haven’t heard of anyone using a Propeller chip for a long time. I’ve had a dev board floating around my collection for at least a decade. I’ve made several false starts at learning Swing but was Propeller 2 cancelled? They were talking about that at the event where I got my board but I still haven’t seen one! And with so many great micros out there using more common languages… is there any reason to invest the time?

    Asking because I need to reduce that pile… both of stuff and goals.

    1. you needn’t learn Spin to work with Propeller.
      I’ve been enjoying C coding on Propeller I & II using this tool: https://www.patreon.com/totalspectrum/posts
      that also supports Basic and Spin “objects” linked together. I also like Taqoz Forth, built into Prop2. Played a bit with Lisp, also built into Prop2. This tool, FlexProp, also gives easy access to a sort of file-system commandline terminal right on the Prop.

  5. Bill – always love seeing your (too infrequent!) articles on HaD. Thanks for writing this one up. How can we entice you to write more than about 1 or so articles per year? :-)

    Brings back fond memories. About 10 years ago, I hit up eBay for a working C64 and found an original, excellent condition M.U.L.E. disk for my younger brother for his birthday. It was in commemoration of the hundreds of hours we played that game back in the 80’s. Ahhhhh … good times.

  6. Was watching this during lunchtime at work, and smiled when I saw my HEARTS128 in the 80-column games folder. It’s surprising how random things will pop up on the interwebs decades after you’ve written them.

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