In the early days of computing it was really hard to get your hands on an actual computer, because they were obscenely expensive and often massive. In the 1960s, most people could only get access to a computer through a university or large corporation. But people still needed to learn the fundamentals of computing in order to help drive the burgeoning industry forward. That’s why pseudo-computers that mirrored many of the operational principals of real computers at the time were sold to universities. The DEC H-500 Computer Lab was one example, and Michael Gardi shows how to make your own functional recreation.
DEC (Digital Equipment Corporation) made a name for themselves with the popular PDP line of minicomputers that were sold from the late ‘50s until the end of the ‘80s. The DEC H-500 Computer Lab resembles some of those PDP computers on a superficial level, but was much smaller and far more affordable. It wasn’t capable of reprogrammable operations like its PDP contemporaries, but the H-500 Computer Lab could be rewired via a point-to-point patch panel in order to perform many specific operations. Students could, for example, use it to perform Boolean algebra and simple digital logic. By building your own replica, you can do the same and follow along with actual workbooks from the era!
Gardi wanted this recreation to look like the original H-500 Computer Lab and to work in exactly the same way. The frame is made from wood, and most of the other parts, including the iconic switches, are designed to be 3D-printed. Instead of duplicating the original electronic circuits, which would have likely required components that are hard to acquire today, Gardi chose to use a modern Arduino Mega board as the heart of the system. You will, however, still get completely functional patch panels. There are a total of 350 patch points, each of which has an era-appropriate plug made with a “rolled flange head eyelet.” A lot of work is required for this build, and our short article here barely scratches the surface, but this recreation is absolutely worth the effort if you want to experience early computing history for yourself.