SPACEWAR! Switch Boxes for a PDP-12

Michael Thompson michael.99.thompson at
Sun Sep 23 09:46:48 CDT 2018

Visitors to the RICM like to play SPACEWAR! in the PDP-12. Unfortunately
using the console switches is uncomfortable, not intuitive, and is tough on
the switches. We would like to recreate the switch boxes used on the PDP-1
to make playing a better experience.

We modified the source
from D.E. WREGE
to use the LINC SXL instruction to read the PDP-12 GPIO signals, and
prototyped two switch boxes using recycled toggle switches. This works
great, so now we need to make better switch boxes.

This CHM article shows what we want to recreate.
This article shows a sketch of the switch boxes.
A generous donor made these boxes for us.

The lever switches are turning our to be difficult to find at a reasonable
price. We found some NOS SwitchCraft lever switches that looked like the
sketch and the PDP-1 pictures and were a reasonable price, but our order
was rejected because they only had one in stock. eBay has Mossman and
SwitchCraft, but they are either very expensive (more than $50 each), or
they only have one available.

The switches that we are looking for need to be SPDT, three-position,
non-locking, center off. (If the switches have more than one pole we can
remove the extra poles to keep the operational force low.) Before we cave
in and buy some modern C&K toggle switches, does anyone have a source for
Mossman or SwitchCraft switches at a reasonable price?

Michael Thompson

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