Multifunction Parallel Port Driver
The Multifunction Parallel Port Driver (mfpd) controls
access to the parallel ports in the system. Various types of
devices such as printers or tape drives may be connected to
the parallel ports. The drivers for these devices access the
associated parallel port hardware only after requesting, and
subsequently having been granted, control of each port by
the mfpd driver. A driver that requests control of a particular
port may have its request denied if access to that port
has already been granted to another driver. In this case, a
driver-supplied callback routine is used to notify the
requesting driver when the desired port has become available.
Once access to a parallel port is granted, the driver
is free to access the port hardware as required. After using
a port, each driver must relinquish control of the port to
the mfpd driver. No driver is permitted to access the parallel
port hardware without first obtaining permission from the
The mfpd driver is implemented as a loadable driver module.
Drivers that access the parallel port hardware must include a
dependency reference to the mfpd driver in their configuration
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004