HSQ(4) BSD Kernel Interfaces Manual HSQ(4)
hsq -- multiplexing serial communications interface
hsq0 at isa? port 0x140 irq 10
com* at hsq?
The hsq driver provides support for Hostess (www.comtrol.com Comtrol
Corporation) 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
device 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.
com(4), intro(4), isa(4)
The hsq driver was written by Denis A. Doroshenko based on the ast(4)
BSD April 29, 2017 BSD