Source of Uncertainty

Have made two of the boards for the Buchla Source of Uncertainty. This board is the SRV or Stored Random Voltages. It is basically a Pseudo Random Sequence that is created from a couple of shift registers. The pseudo random sequence is 15 bits long and cycles every 32767 clocks. If you look carefully you can see the results of some simulation of the circuit on the paper behind the board. The resistor values that Don Buchla choose are a closest approximation from standard resistor values, hence the jaggies. The board is a layout by vtl5c3 and can be found here. I have found a couple of mistakes which I am currently fixing up and will post back to the newsgroup when I have verified the fixes.