HSQ(4)                    OpenBSD Programmer's Manual                   HSQ(4)

NAME
     hsq - multiplexing serial communications interface

SYNOPSIS
     hsq0 at isa? port 0x140 irq 10
     com* at hsq?

DESCRIPTION
     The hsq driver provides support for Hostess (Comtrol Corporation,
     www.comtrol.com) and compatible boards that multiplex together up to four
     EIA RS-232C (CCITT V.28) communications interfaces.

     Each hsq device is the master device for up to four com devices.  The
     kernel configuration specifies these com devices as slave devices of the
     hsq device, as shown in SYNOPSIS.  The slave ID given for each com device
     determines which bit in the interrupt multiplexing register is tested to
     find interrupts for that device.  The port specification for the hsq de-
     vice is used to compute the base addresses for the com subdevices (they
     are equal to port + ID * 8) and the port for the interrupt multiplexing
     register (it is equal to port + 7).  More technical details on how the
     driver works can be found in the big comment at the beginning of the
     driver's source code.

     Information on setup of card's configuration switches should be taken
     from Comtrol Corporation's web site, since the author wrote and tested
     the driver only with Hostess-compatible cards.

FILES
     /dev/tty0?
     /dev/cua0?

SEE ALSO
     com(4), intro(4), isa(4)

HISTORY
     The hsq driver was written by Denis A. Doroshenko based on the ast(4)
     driver.

OpenBSD 4.7                      May 21, 2008                                1
