Maker Faire

Full-scale Functional Replica of a DEC PDP-1 Computer

Type: Maker Table/Exhibit
Program Area: Computers

Day/Time: Saturday and Sunday

Location: Fiesta Hall

This is a full-scale, functional replica of Digital Equipment Corporation's first complete computer product, the PDP-1, introduced in 1961.

There are many things significant about this computer (including possibly being the "first" "personal computer") but the most significant perhaps is that this is the computer on which Spacewar! (the first videogame) was developed.

The replica features a functional front panel with blinking lights and switches. The front panel is connected to a custom controller board that is interfaced to the parallel port of a standard PC. The PC runs an open source emulator called simh, and on top of that runs a graphics simulator that simulates the original point plot graphics display of the PDP-1. The original MIT Spacewar! code was then loaded into the simulator allowing people to play (a very close proximation) of Spacewar! on the replica complete with phosphor persistence traces.

I hacked some code for the front panel controller into the simh program so that the simulator (and thus the game) can be controlled from the front panel just like on the real thing. I also constructed replica joysticks that are based on photos and drawings of the original joysticks produced by the MIT gang back in the 1960s.

The first replica was commissioned by the National Science Museum of Tokyo, and was installed there for a videogame exhibit in the Fall of 2004. I'm currently constructing a second replica for my own pleasure, which I will bring to the Maker Faire.

Related site: http://www.vintage.org/gallery.php?grouptag=PDP1REPLICA

Photo

Presenters

Sellam Ismail, Proprietor
Maria Ismail, Assistant
Leo Ismail, Apprentice

I'm a Computer Historian and Consultant. Among other things, I build replicas of ancient computers for museums, and I also run the Vintage Computer Festival (www.vintage.org) which is a celebration of computers and their history. A lot of my work requires restoration of old computer hardware so that I can use them to retrieve old data or to include them in exhibitions. A lot of times I have to build some sort of custom interface to connect an old disk drive or what not to a modern PC. You can learn more about my consulting services at my VintageTech website (www.vintagetech.com). It's what I do for fun, but for some reason people are compelled to throw money at me to do it. Go figure.