== Cassette Motor Relay ==
Switching the casette Motor On relay on or off can produce a 'click' sound(done via [[8255|PPI Port C, Bit 4]]).
* Works only on 664 and 6128 (which contain a relay for use with external cassette drives).
* Does not work on 464 and 464+ (which have internal transistor-driven tape drives without relays).