That screen was just telling you whether the switch was on or off, though - the logic to decide what to display was just a series of jumpers in the case front.

That screen was just telling you whether the switch was on or off, though - the logic to decide what to display was just a series of jumpers in the case front. That's why some were configured to read |_| | | | | and | _ |_ |_| instead. It's not like it was actually measuring the bus frequency.