The PDP-9 will now execute the built-in diagnostic described section
3.7.7.3 of the maintenance manual. This diag copies the contents of
the AR register go through the ADR to increment the value, then to the
MB register and then back to the AC, AR, and PC registers. This means
that much of the I/O bus logic, the CP timing, the registers, the ADR,
and the Control Memory is working. Now we need to fix the core memory
controller and start debugging the rest of the processor and I/O.
--
Michael Thompson