Hackaday Prize Entry: A Mess Of VGA On A Breadboard

Before all our video games came over the Intertubes, before they were on CDs, and before they were on cartridges, video games were all discrete logic. Pong was the first and you can build that out of several dozen logic chips. The great [Woz] famously built Breakout out of 44 simple chips.

For [Marcel]’s entry to the Hackaday Prize, he’s taking the single board microprocessor-less computer to the next level. He’s building a multi-Megahertz 64-color computer on a breadboard. What’s the capacitance of a breadboard? Just ask [Marcel].

The design of this disintegrated computer has just about everything you could want in a discrete CPU. There is no microcontroller or complex chips like the 74181 ALU, there’s pipelining with sometimes two instructions per clock, decoding with diodes, and a 60 Hz, 64 color VGA output and four sound channels. There’s only about 40 TTL chips on this board.

The project logs for this Hackaday Prize entry are a treat in themsleves, ranging from topics to the implementation of NES controllers to getting rid of the breadboard and turning this computer into something like a vintage game system, but with a custom CPU and instruction set. It’s an amazing build, and an awesome project for the Hackaday Prize.

16 thoughts on “Hackaday Prize Entry: A Mess Of VGA On A Breadboard

    1. Wire wrap computers get out of hand fast. A few years ago I had five or six boards, 80-100 chips each, all wired together into most of a quad core 8 bit computer.

      Unfortunately I was 13-17 when I was building things like that, and my budget was low (crap socket quality) and my experience was low (made poor board interconnect connections, unstable oscillators, fanout issues, noisy interconnect wiring, etc.) so while a lot of the various computer designs ran, few of them ran reliably enough to ever finish. Except for Lefty, (a computer I managed to wire entirely backwards), but that had no provision for entering programs other than DIP switches.

      Now that I have the skills to finish that stuff I no longer have the time. Also the little TVs I bought at good will to house the boards in are mostly taken apart beyond being useful anymore. I had the tendency to do that.

      1. Dec PDP-11/70 and Vax were loaded with WW. I wrapped big PCBs of 74HC and 74ACT to prototype ASICs. In fact, I think I still have a Gardner Denver gun. The reason I bring it up is, WW is robust and better than soldered joints at handling flexing and vibration. So, you can move it around and transport it and still be nearly as easy to change as the breadboards.

        1. Oh, it’s probably the best way to make computers out of chips like these, that’s why designs can get so huge and out of control.

          So long as you know how to get signals off of the boards, at least.

    1. Sure, but here the VGA signals come straight out of a flip-flop stage that buffers them while the next pixel is on the way. Having said that, the pixels are a better defined in the PCB version than in the breadboard version. Ground and Vcc references are more stable on the PCB.

  1. So when will the results be published? The official rules say they should have been published yesterday (or “around”), but obviously weren’t. Are the rules only binding to the participants, and not to the organizers?

  2. Dating the project is difficult because almost everything is early 1970s chips, but it uses a large raster memory (32kb) which would have been prohibitively expensive in early 1970s. However, you could scale that for the time. Maybe an early 1970s version would have a smaller RAM with large blockiness, and later you just scale the RAM as it gets cheaper. But you would definitely be cheaper than other similar products since you save the cost of the microcontroller. And you could easily add a keyboard to make it a computer instead of a gaming system. Great work!

  3. Pong with a dozen chips??? I used to own an original arcade pong machine. It had 6 huge circuit boards in it with about 50-60 chips per board. It had a 100 Amp power supply. Weighed a ton. Not sure when it was built, early 70’s I would guess. Continued to work well into the 90’s.

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