PiDP-8/I – remaking the PDP-8/I

We often see really fantastic looking retro builds that are one-offs; so you can’t replicate them at home without a lot of artistic and mechanical skill. So we were really pleased when Oscar Vermeulen emailed us yesterday about the project he’s been working on. As well as having made something that’s both functional and utterly desirable, he’s had the smarts to make a number of kits available to buy. This is it: a simply beautiful replica of the PDP-8/I.

pdp8

For comparison, here’s the original, courtesy of VintageComputer.net.

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Even I’m not old enough to remember these first hand. The PDP-8 was the first computer that came in at less than the size of a house to find commercial success. The original PDP-8, launched in 1965, was around the size of a fridge and weighed about 160lbs (with 60lbs of that weight being the power supply). Subsequent generations like the PDP-8/I were smaller, and could be used on a desktop or rack-mounted. DEC made and sold more than 50,000 PDP-8s altogether, before they were displaced from the consumer computing market by things that look more like the desktop computers we use today, like the Apple II and IBM’s first PCs. (If you’re interested in digging some more into the history of the PDP series, there’s a fascinating article from the Computer History Museum in Silicon Valley you can read, along with lots of detail about architecture and programming the machines on Wikipedia.)

The Raspberry Pi version is a pretty faithful replica. Here’s Oscar to explain more.

Oscar’s replica is open-source hardware, so if you do have the wherewithal to make your own, everything is made available for you to do just that. He says:

From a hardware perspective, the PiDP is just a frontpanel add-on for a Raspberry PI. In the hardware section below, the technical details of the front panel are explained. In fact, the front panel could just as easily be driven by any microcontroller, it only lights the leds and scans the switch positions.

From a software perspective, the PiDP is just a Raspberry Pi, running the Raspbian flavour of Linux, which automatically logs in to the SimH emulator. SimH is modified to drive the front panel in the appropriate manner – meaning it has instructions added to reflect the state of the PDP-8 CPU registers through the leds, and responds to the switch settings.

It’s a neat solution that looks fantastic, and is faithful to the original hardware.

Front panel from behind

Front panel from behind

To get your hands on your own, head over to Obsolescence Guaranteed, Oscar’s website, and join the mailing list; the next batch of kits is going out in October.