Kenbak to the Future

Usually when someone says “they don't make them like they used to,” they are lamenting the modern proliferation of cheap, mass-produced products that are not built to last. But sometimes it is actually good that things are not made like they used to be. Consider personal computers, for example. While many members of the Hackster community — myself included — love to play with retro computers, I think we can all agree it is good that a top-of-the-line personal computer of today is orders of magnitude more powerful than, say, a Commodore 64.

But that does not mean that we cannot spend some time with these machines for both fun and education in our spare moments. Those that want to go back to the very beginning of the personal computing revolution would need to start with the Kenbak-1, which was first sold as a kit in 1971. Personal computing was not exactly at the forefront of most people’s minds at that time, however. Only about 40 of these computers sold, so they are exceedingly rare today and it would be nearly impossible to get your hands on one.

But YouTuber Artem Kalinchuk has brought this platform back to life by creating a modern reproduction that anyone can build at home for a small fraction of the original selling price. The Kenbak-1 will seem very foreign to a modern computer user in almost every way imaginable. Its programming interface and output device consisted of switches and lights on the front panel of its case. Also very strange by today’s standards, the Kenbak-1 had no microprocessor. All of the logic was implemented by a variety of TTL chips.

In order to reproduce this classic machine, Kalinchuk first tracked down a PCB design that mimics the original board — big, wide, wavy traces and all — and had one manufactured. Aside from that, 131 7400-series ICs were required, most of which are still readily available today. A handful of chips, like the shift registers that make up the Kenbak-1’s odd 256 byte serial memory bank were sourced on secondary markets. The remaining electronic components consisted of a handful of resistors, capacitors, fuses, and so on.

As for the casing, original specification documents with measurements were obtained and utilized to create reproductions in CAD software. The design files were then sent off to PCBWay to manufacture the parts in powder-coated steel and brushed aluminum. The switches and lights of the front panel were replaced with modern components since the originals are virtually unobtainable. The result looked beautiful, although it was noted that it was very expensive and efforts would need to be made to bring costs down.

As of this writing, Kalinchuk had everything lined up to start assembling the computer and testing it. Be sure to stay tuned so you can be one of the first to see this classic computer being fired up. If you want to get started making your own Kenbak-1, you can find the PCB design files here, and the CAD files for the case here.