I was sorry to see the death of the slow mainframe computer. One could go down to the computer room, look at the computer through the large, glass window, and gauge the sort of response time one would get when accessing it from the terminals up on the second floor.

And the golden age of digital display was the nixie tube. The anodes were aligned at varying depths when seen from the front and typically not arranged in numerical order. Thus the display of digits, when counting up, as may happen when displaying a changing voltage, would skitter back and forth in a seeming random manner. The tube, of course, is known in British English, which we all know is far superior to the degraded American English, as a valve, despite the fact that it is nothing at all like a folding door.