[sdiy] TB303 CPU update, still not working

[Robin Whittle]

The 6 small pots along the top of the TB-303 main board provide a ground
link to various parts of the circuitry - through their metal bodies.

The CPU needs power, a clock circuit (pins 1 and 42) which it should
make resonate, and an interrupt signal on pin 6.  If these are active
and the CPU is good, then the CPU should be scanning the switches and
LEDs.  It won't run as a sequencer unless it gets Run/Stop and Clock,
which it reads as part of the switch scanning matrix, via IC7 and the
transistors to the left of that on the schematic.

  - Robin

  http://www.firstpr.com.au/rwi/dfish/