Sharp RT3151 - Anybody Know Anything?

[greenhomeelectronics]

Hi Folks, I have got my mitts on a rather interesting cassette deck - or rather "electronic tape processor" as the front panel legend states. It all seems to be working but I can't work out exactly what the numbered buttons are for. I have been able to set the clock, the counter works etc but I think there is some sort of indexing system. Anybody know anything about it?
Here is a photo in the hope it will jog some memories:
Thanks in advance,
Dave.

[technobear]

I believe the music indexing function is simply a music search function that looks for and counts the gaps between tracks.

I think this deck was one of the first to have a built in timer for unattended recording complete with a switched AC outlet for powering up e.g. a tuner at the programmed time.

This is an antique now. Must be from the late seventies.