SupraTurbo 28?
Since you have a 2000, the pass through is not relevant. It is only used on
the 500 version. Since the 500 only has 1 expansion port, many of the
peripherals designed to use that port will pass the port signals through
allowing other devices to connect. On my system, the Supraturbo 28 is attached
to the 500 and my hard drive unit is attached to the Supraturbo.