Looking at the PCB, it has a 50-pin and a 20-pin
connector.
Is that SA4000?
SA1000
SA4000 was the 14" drive.
AED sold these drives in their WINC08 RL02 emulating drive product.
Compupro sold them as well.
There was an ANSI standard number for the interface, but I don't
remember
the number off hand.