82161A Digital Cassette with Audio Tapes?

[Paul Berger (Canada)]

One thing that is likely missing on the audio tapes is the holes to sense EOT and BOT, nor is it likely to have the small 45 degree mirror that reflects the light through that hole to the sensor.

I am not sure which tape you are referring to but I just compared a 82161A cartridge to a Sony MC-90 and the spacing of the holes for the spools is even different.