The other piece is a round wiring cable with a
DB-25M connector on
one end and a male and female HP-IB(?) connector on the other. The cable
is black and about 6' long. Anyone know what these are for?
IEC625 is the same signals as IEEE488 but on DB25 connectors. Maybe it's
for that. PERQs use the DB25 connector for the IEEE-488 bus, I think with
IEC625 pinouts. I guess other machines did too
-tony