I recently sat down with Fred Yearian, a former Boeing engineer, and Jeff Kaylin, an engineer at Living Computers, to talk about their restoration work on Yerian’s PDP-7 at Living Computers: Museum + Labs. The PDP-7 (short for ‘Programmed Data Processor’) was introduced by The Digital Equipment Corporation (DEC) in 1964.
To find a PDP-7—particularly one that is operational—is exceptionally rare. To find one unknown to people is remarkable:
LCM+L’s PDP-7 was originally installed at the University of Oregon’s nuclear physics department. After Professor Harlan Lefevre accepted delivery of the system, his lab spent the next three years writing the necessary software required to carry out their research. Once complete, the system proved remarkably reliable: over the next four decades, it logged more than 60,000 hours of use and enabled 23 graduate students to earn their PhDs.
Up until the discovery of Yearian’s machine, LCM+L’s PDP-7 was believed to be the only operational PDP-7 left in the world. Chuckling to himself, Yearian recalls hearing this history presented during his first visit to LCM+L.
“I walked in the computer museum, and someone said ‘Oh, this is the only [PDP-7] that’s still working’.
And I said, ‘Well actually, I got one in my basement!’”
On November 7th, 2018, after over a year of correspondence following Yearian’s initial visit, a handful of Living Computers engineers … arrived at Yearian’s house to extract the PDP-7 from his work room and load it onto a truck bound for the museum.
From there, the team began working to load the UNIX Version 0 operating system onto the machine. This goal was an homage to the fact that Ken Thompson wrote UNIX Version 0 on an old PDP-7 at Bell Labs in 1969. UNIX also turned 50 this year, which made the restoration project all the more timely.
After countless hours of work, the team booted UNIX v0 on Yearian’s PDP-7 on Monday October 28th, 2019 for the first time. The engineers logged in as user ‘dmr’ as a tribute to Dennis M. Ritchie, who created UNIX with Ken Thompson in 1969.
Adafruit publishes a wide range of writing and video content, including interviews and reporting on the maker market and the wider technology world. Our standards page is intended as a guide to best practices that Adafruit uses, as well as an outline of the ethical standards Adafruit aspires to. While Adafruit is not an independent journalistic institution, Adafruit strives to be a fair, informative, and positive voice within the community – check it out here: adafruit.com/editorialstandards
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat and our Discord!
Python for Microcontrollers – Adafruit Daily — Python on Microcontrollers Newsletter: CircuitPython 9.2.1, What is DMA, PyConUS 2025 and More! #CircuitPython #Python #micropython @ThePSF @Raspberry_Pi
EYE on NPI – Adafruit Daily — EYE on NPI Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey
