Homebrew 8-bit computer

A recent high-school grad named Jack Eisenmann homebrewed his own 8-bit computer, wiring up a custom CPU and GPU, writing an OS and hex editor, and producing a suite of demo apps including some fun little games:

Jack Eisenmann, a programmer who just graduated high school, has built his own 8-bit homebrew computer completely from scratch using an old keyboard, a television, and a ton of TTL logic chips. No, he didn't buy some computer parts and snap them together; he blueprinted every wire and connection and then built it, wire by wire. After he finished construction, he had to teach it how to communicate, so he created his own operating system and wrote some games for it. That's dedication.
Duo Adept: An 8-bit computer designed and built by Jack Eisenmann, a high school student.

High school grad builds 8-bit computer from scratch, complete with custom OS and Pong (Yahoo News)

(via Engadget)


  1. This is the way to learn. There’s always some ambiguity in the data sheets that is only cleared up when you try to use the chip. Sixty years ago all logic was done with relays. We called it pinball logic. By the time you’ve worked out how to do tic-tac-toe with a mess of relays you’ve nailed down some important concepts. Trying to go from pencil sketch to working stunt box teaches many lessons.

  2. Excellent work! Back in the day this would have been a cover-story feature in Byte magazine. Now, can you get it to sing Daisy Bell? :P

  3. That’s the way we used to have to do it. I never built my own cpu but I did build a 32000 based workstation and custom graphics card, wrote a simple solid modeller and built a 6DoF input for it all. In 1982. To help design and build motorcycle chassis.
    Nice to see someone delve that deep again. He should talk with Jeri Ellsworth and see if her plans to make custom chips in the garage might allow for making integrated cpus of his design.

    1. I have no real concept of how much work that is, or just what level work it is in terms of modern computer science, but the dedication and detail in execution is absolutely impressive in an 18 year old.

  4. That is both impressive and very fun. It amazes me how the primitive graphics and blocky text immediately take me right back to the days of machines such as the TRS-80 and VIC-20 and Saturdays spent with Compute! magazine.

    It resparks the lost and nearly forgotten childhood wonder of computers that I had back then. His creation is just loaded with personality!

    With modern computers everything is so perfect and polished and optimized for human interaction. Compared to something like this, they just seem like soulless appliances.

  5. Yeah, me too. I don’t understand any of it but that doesn’t mean I can’t have an appreciation for this young man’s talent. In a day when others his age are hacking, he’s building some pretty cool stuff; maybe his next project might be a pretty sweet Cuda.

  6. Every Jack Eisenmann cancels out 1000 Gucci Manes. There’s hope for the youngsters after all.

  7. Its more true to life using TTL I suppose, but you can get the same result with the equivalent CMOS chips with a fraction of the power consumption. I wonder if this guy had to install a high current mains power connection? Maybe three phase power and a huge aircon?

  8. I’m not worthy, I’m not worthy!!!!

    Seriously… I’m so seriously… flabbergasted! Seriously good job!!!

    And yes, watching that video brought back memories of my old Vic-20! And now I want to do something like that, too, but I know I won’t. But one can dream!

    A big high five (I want to give a big hug, really, but that would be a bit creepy, so I’ll settle for a high five) from one programmer to another. Age doesn’t matter in the programming world, skills does, and this dude has some mad programming skillz!!!!

  9. CMOS is more electrically fragile than TTL, or it was back in the 80s when I was paying attention.

  10. This is some really amazing stuff. The average person might not think this is cool anymore, but those in the know understand the significance of being able to make something like this. From the demo, this system seems very well designed and this kid will go far with this kind of skill.

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