Vacuum Tube Computer Part 22: CPU Complete!

As 2021 comes to a close, so does the first phase of the vacuum tube computer project with completion of the central processor unit (CPU). Although the computer still lacks memory and input-output facilities, it now does everything the Motorola MC14500B one-bit industrial control microprocessor upon which it was modeled did, plus a few extra twists and tricks. After beefing up the power supply to cope with a table top full of tubes, it is now possible to exercise the processor with a manual control panel and verify its correct operation.