The ddb file is an old Protel 99 databse file.

Schematics and PCB have been exported as pdf for convenience.


WARNING: the tube PCB is *wrong*. I had inverted left/right pins on the tubes. This
is not a big deal, because the software has to remap the pins anyway BUT it is a problem
for the anode (obviously !). So only 2 pins should be swapped (the anode and the digit next
to it). I haven't corrected this on the PCB (hence the pdf is wrong too), but it is easy to
do. Remember that this is just a prototype that I realized in order to develop the firmware,
and I don't have other GR-116D tubes (which is unfortunate, because they are wonderful).
