HPIBBUS(4)            OpenBSD Programmer's Manual (HP300)           HPIBBUS(4)

NAME
     hpibbus - HP-IB bus interface

SYNOPSIS
     hpibbus*  at nhpib?
     hpibbus*  at fhpib?

     hd*  at hpibbus?                  (disks)
     ct*  at hpibbus?                  (cartridge tapes)
     mt*  at hpibbus?                  (9-track tapes)
     ppi0 at hpibbus? slave 5 punit 0  (plotter)

DESCRIPTION
     HP-IB is essentially an IEEE 488 bus, with an HP command set (CS/80 on
     `newer' devices, Amigo on before-the-early-1980s devices) thrown on top.
     Devices that respond to CS/80 (and probably Amigo, too) are tagged with a
     16-bit ID.

     HP-IB has a 2-level addressing scheme: slave, the analog of a SCSI ID,
     and punit, the analog of a SCSI LUN.

     The CS/80 ID is unique to the slave, and is shared by all its punits.
     Most devices only have one punit; multiple punits are often used for disk
     drives that have an accompanying tape drive on the second punit, or for
     dual floppy drives.

     In addition, not all HP-IB devices speak CS/80 or Amigo.  Examples of
     such devices are HP-IB plotters, which simply take raw plotter commands
     over 488.  These devices do not have ID tags, and often the host cannot
     even tell if such a device is attached to the system.

SEE ALSO
     ct(4), hd(4), intro(4), nhpib(4), ppi(4)

OpenBSD 4.7                      April 1, 2008                               1
