Angelo Papenhoff's Open Source Blincolnlights 18 Front Panel Delves Back Into Computing History

Computer historian Angelo Papenhoff has put together a front-panel filled with blinking lights, designed for an unusual breed of vintage system: machines with an 18-bit word length, including the Whirlwind I.

The computers I wanted to use this panel with are: the TX-0, one of the first transistorized computers, mid 1950s," Papenhoff explains of the project. "The [DEC] PDP-1, a sort of successor to the TX-0, famous for Spacewar! ~1960. The PDP-4, similar to PDP-1 but not the same. 1962. The PDP-7, same architecture as the PDP-4, first machine to run UNIX. 1965. Possibly the PDP-9 and -15, same architecture again, also (briefly) ran UNIX. [And the] Whirlwind I, the ancestor of all of the above."

Development of the Whirlwind I began at MIT's Servomechanism Laboratory in 1947, as part of a US Navy operation to create a computerized flight simulator for bomber crew training. One of the first systems to offer parallel computing capabilities to boost performance, the machine was also the first to make use of the at-the-time shiny new magnetic core memory technology — a far better system for storing data than the mercury delay lines of previous machines.

"[It was] probably the first computer that was designed for high reliability, real-time and interactive use," Papenhoff writes of his interest in the Whirlwind I, "being a piece of and controlling a system rather than doing pure number crunching, and as such the spiritual grand-daddy of the modern microcontroller."

The front-panel project itself is inspired by the work of Oscar Vermeulen on creating the PiDP family of Raspberry Pi-powered DEC PDP replicas. Where Vermeulen focused on devices with a 12-bit word length, though, Papenhoff's front panel uses 18-bit word lengths to match the target systems.

"The pinout is compatible with the Raspberry Pi GPIO [General-Purpose Input/Output] header," Papenhoff notes. "This makes it compatible with widely available hardware and easy to use. However, eventually I also want to hook up FPGAs for more timing-accurate simulations."

Build details, and a parts list, KiCad project files, and Gerbers, are available on Papenhoff's Hackaday.io page, under an unspecified open source license.