introduction to HP 9000/700 GSC bus support
gsc* at lasi?
gsc* at asp?
gsc* at wax?
The General System Connect (GSC) bus is the core I/O bus for all HP 9000/700
workstations. All I/O subsystems connect to this bus. The devices can be
either on separate chips, expansion cards or on an integrated megacell, like
the LASI MBA.
The GSC bus is a 32-bit wide, address and data multiplexed bus. In its
"standard" implementation it has a maximum throughput of 160MB/s,
the "2x" implementation reaches up to 250MB/s. Some HPPA CPUs
directly attach to this bus, namely the PA7100LC and PA7300LC.
As for the expansion cards, there are different form-factors, depending on
bus-speed (standard or 2x) and specific models. The standard formfactor is the
"EISA form-factor"; cards that look like typical EISA cards with a
different connector (100-pin female EBBL). The Series 712 have their own
special type of GSC expansion cards, called the "GIO form-factor",
which is quite small and mostly has only one VLSI chip on it (in most cases
LASI/WAX). Newer systems sometimes feature the "HSC formfactor",
which is a 1U-VME card-like expansion card with a 100-pin male pin+socket
connector. Mixing cards with different speeds is supported but downgrades the
performance of the whole I/O-subsystem.
provides support for the following devices:
- Siemens PSB2160 audio codec
- serial communications interface
- PC-style keyboard controller
- CS4215/AD1849 audio
- introduction to HP-HIL support
- Intel i82596 Ethernet device
- parallel port driver
- Symbios/NCR 53C700 SCSI I/O Processor
- Symbios/NCR 53C710 SCSI I/O Processor
Some of these GSC devices also have PCI, EISA, or ISA equivalents. These are
listed in pci(4)
driver appeared in OpenBSD