You would most likely see Kennedys on minicomputers,
especially
in aftermarket upgrades. PDP-11's, DG's, etc.
One of the odder things I've acquired over the years is a tape controller
made bu a company called 'Dylon' that has an HPIB host interface. I
forget what drive I have hooked up to it, I think it's a Kennedy. The
interface is standard Pertec unformatted, so many drives would work.
Anyway, the programming maual (I have it, and the service manual with
full schematics) gives example programs for the HP9825 desktop calculator
(!). For a joke I occe linked it to an HP71B pocket computer via an
HP82169 HPIL-HPIB translator. It worked perfectly (of course). Not a lot
of use for a 9-track tape drive on a pocket machine, but...
-tony