[HarmlessLovableFuzzball]

I take considerable pleasure in seeing that a controller I built in 1975 is still operating."

What exactly do you mean by 'controller' ?

[William Tell]

HarmlessLovableFuzzball said: "What exactly do you mean by 'controller' ?"

It's a controller of a motor which is handling semiconductor materials during processing. The motor behavior is controlled by operator settings and feedback to the operator is supplied to verify the operation.

The application would be rather trivial using a microcomputer; but such were not available then.