Improve GAL testing and fix various bugs

Plot DFP PCB (rev 2133a) and create order

Produce revision 2134 for peripheral backplane

Prepare PB0 r2119 gerbers

Processor Backplane 2134 (a) as sent to JLCPCB.

Tagging just before switch back to DIN 41612

Tag last updates of DFP2 revision B.

Documented memory and ALU instructions

Last DFP 1 firmware.

PCB for DFP revision 1939 is now being manufactured.