See the flickr set for photos and videos (and a lot more information).
The KENBAK-uino sketch (code) is available here. It includes a schematic and additional documentation.

FWIW, the PostScript file for the legend etc is here too (there's a fair bit o' cruft in the file).

You can now buy a very professional kit, which runs this code: The μKENBAK-1!

The code is now on GitHub.