Another HP 9915, Wahoo!

[Joe R.]

  I went scrounging a couple of days ago and one of the things that I found
was a  HP 19" rack mount unit called a HP 5181A Display/Tape Storage Unit.
I grabbed it without looking too losely. Today I checked it and found that
the RH side of the unit is a HP 9915A computer! The LH side is a HP 1332
X-Y CRT display. No idea what the whole unit is for. Anyone know?  I
couldn't find anything on the net about it.

     Joe