Probably just the nature of the sort of chips you could buy at the time and their scan rates and debounce circuitry. As time marches on we have added a lot of

Probably just the nature of the sort of chips you could buy at the time and their scan rates and debounce circuitry. As time marches on we have added a lot of abstraction into the mix. One thing I used to do to make old DOS computers 'feel faster' was to turn up the keyboard rates in the BIOS.