Tony Duell wrote:
The digital tapes have an extra notch in the rear edge
of the cassette
shell.
And it's not in the middle of the rear edge, either. I have a Philips
cassette drive that uses the off-centre notch to detect Side A or Side B
of the tape. It has two microswitches in the back of the cassette
space, only one of which will fall within the notch.
--
John Honniball
coredump(a)gifford.co.uk