HP used to make some whizzy desk top machines, 9845, that used their own 16 bit CPU. The tape drives in these machines also used a much smaller, presumably simpler, custom CPU. These have 48 pins, they are a slab of ceramic with gold contact points.

Just found what I think are two of these, anyone know anything about them? They were in an ancient comms tester with a 2Kx8 core store.

Markings

1AA6 6004 12691 3581
1AE8 6001 12450 2381

The last must be the date, but why are the other markings not identical?