The Gigatron TTL microcomputer is a minimalistic retro computer. It’s special in its own oddball way, because it has absolutely no complex logic chips in it, not even a microprocessor! Its CPU is built out of a handful of classic 7400-series ICs, colloquially known as the TTL logic series. These chips combined form a powerful 8-bit processor.
Besides running applications, this processor performs functions that traditionally require dedicated peripheral chips for video, sound and other I/O. By eliminating these the hardware remains small and understandable. Still the single-board system works as a full-blown microcomputer that you can play video games with.
Now you can easily build one yourself. As you build, learn what happens inside a CPU by looking inside one. See the functional units, look inside the Arithmetic and Logic Unit, see its truth tables and learn what makes up a ROM. Then go on to enjoy playing the built-in retro video games or write little programs in BASIC. You can also hack it in any way you like if you have a taste for that.
[Click on the image to enter the Gigatron emulator by Phil Thomas]
Gigatron is a TTL microcomputer that you build yourself. It was sold as a solder-it-yourself kit from 2018 to 2020. No kits will be produced anymore by us.
But you can still build one. What you need is the following:
The circuit board. You will have to have this made at your favourite PCB maker. You will need to upload the design files for the Gigatron and Pluggy McPlugface that we have made available;
All the electronic parts. We provide a Bill of Materials that lists what you need to get. We do not provide support;
The full-color assembly manual also containing schematics and a soldering course ;
Optional: a box to put the Gigatron in. The shiny, mahogany colored, wooden case with plexiglass viewing window that was offered by us is no longer being produced;
A soldering iron, solder and a multimeter;
An universal programmer to program the EPROM and ATTiny, google for TL866A;
Side cutters and optionally (but handy) some needle-nose pliers;
Something that provides USB power (laptop, USB charger, ..);
A VGA monitor (or a VGA-to-HDMI converter and an HDMI monitor);
Optionally a PS/2 keyboard for using BASIC
A couple of hours to complete building the kit.
How it works
We have given in-depth talks at several hacker spaces. Here is one Walter did at Hackerhotel 2018 explaining both concept choices and design details.
For a PDF version of the slides and for more materials, check out the Tutorials section.
Gigatron is a project by Marcel van Kervinck and Walter Belgers.
On May 25, 2020, Marcel passed away due to an illness. I, Walter, remember Marcel as a great engineer, eager to fully understand the technologies at deepest level. He was also the software guy in the team, having written all the initial software for the Gigatron and Pluggy McPlugface. When using PS/2 libraries for the pluggy, he found bugs unknown until then, which shows his tenacity to fully understand things and make them work as well as possible. We both believed in the beauty of making something as elegant as possible. We created the Gigatron to be a kit to be proud of. And we were. People who have met Marcel at various occassions will surely remember his optimism and the joy he got from talking to similar minded people. I will miss Marcel.
In this talk recorded at VCF Berlin 2019, Marcel discusses the background of this project: from the earliest breadboard experiments to the version that can run Micro-Soft BASIC.
For general questions, feel free to drop me an e-mail. We are also on Twitter, Hackaday and GitHub, all links are listed below under “Find us”. Note that messages sent to Marcel on Hackaday or GitHub will not be read.
The Gigatron TTL computer is now fully open source! The source code had been open source (BSD license) since the beginning of course. A while ago, we published the design files for the printed circuit boards, both for the Gigatron and for Pluggy McPlugface, the PS/2 adapter. We have now also made the full Assembly …
Almost a year ago, we had sold over 500 Gigatrons, much to our own surprise. Since then, a lot has happened. We now have 6502 emulation and the Gigatron can run Apple-1 code, such as WozMon. We have BASIC running and there’s a great BASIC compiler, opening the way to create great games. Looking back …
We are nearing the end of our current stock of Gigatrons. I suspect stock will last for a few months from now. We have decided to stop selling kits once our current stock has been sold. For us, the Gigatron was always about inventing new things, understanding technology, designing, fine tuning, tinkering, and also about …