hpc interfaces the peripherals connected to it to the
gio(4) bus.
hpc is found on the Personal Iris 4D/3x, Indigo, Indy, Challenge S, Challenge M, and Indigo2 machines.
There are three different numerical revisions of the
hpc controller. Revisions 1 and 1.5 exist on Personal Iris 4D/3x and Indigo machines, as well as GIO32bis expansion cards such as the E++ SEEQ-based Ethernet adapter. Revision 1.5 supports bi-endian operation. Revision 3 exists on Indy, Challenge S, Indigo2, and Challenge M systems. It is possible to have an on-board HPC3 as well as HPC1.5-based GIO32bis adapters in the Indy and Challenge S systems. Additionally, the Challenge S may have a secondary HPC3 if the IOPLUS (a.k.a. ''mezzanine'') board is installed.