XIR(4) BSD Programmer's Manual XIR(4)NAMExir - Xircom Pocket Ethernet III parallel-to-Ethernet adaptor
SYNOPSIS
device xir0 at isa? port 0 # on lp0
device xir1 at isa? port 0 # on lp1
device xir2 at isa? port 0 # on lp2
DESCRIPTION
The xir interface provides access to a 10 Mb/s Ethernet network. It sup-
ports the Xircom PE-III parallel printer port adaptor. It uses a hook in
the lp driver to find out what port address and interrupt to use; the in-
terface unit number (N in xirN) is assumed by the driver to correspond to
a parallel port unit number (N in lpN), and the xir devices must there-
fore follow the lp devices in the kernel configuration file (see
config(8)).
If your printer port can be set to different modes, either via DIP
switches or the CMOS ``Setup'' screens, you may wish to try each mode in
turn, measuring your throughput for each. The driver will make use of
``enhanced'' or ``bidirectional'' modes if the port is so configured, but
these modes are not always faster than ``standard'' mode. Due to the
lack of standardization among vendors, some ports which appear to the
driver as ``enhanced'' or ``bidirectional'' may not work at all. You may
have to try several modes just to find one that works.
On some laptop computers, the parallel port appears to support bidirec-
tional transfers or enhanced mode even when you disable these capabili-
ties in the CMOS ``Setup'' screens. The xir driver will deliberately
treat the port as unidirectional and unenhanced if you set the IFF_LINK0
interface flag (using the link0 option to ifconfig(8)). If your Xircom
exhibits poor performance and you cannot find a CMOS configuration set-
ting that improves it, try IFF_LINK0 before you give up.
DIAGNOSTICS
The following diagnostics may be printed during autoconfiguration:
WARNING: xir%d has its own IRQ (%d)
An irq was specified on the xir device in the kernel configuration file.
This is impossible since the associated lp device's interrupt is the only
thing that can work.
xir%d: only one Xircom allowed
The xir driver is currently unable to support more than one adaptor per
system. As the PE-III is primarily used on laptop computers, this should
not present a problem.
xir%d: parallel port busy
If the printer port is in use via its character interface (/dev/lpN) or
by the pe driver, you will not be able to bring it up with the xir driv-
er.
xir%d: failed to initialize
This is a general error condition that indicates a hardware or connection
problem. Re-seating the PE-III and rebooting your computer may help.
xir%d: adapter disconnected: \
(you may need ifconfig down/up to reactivate)
If the adaptor loses power or is disconnected from the printer port, the
driver might not be able to restart it without being told to do so by a
command like ``ifconfig xirN down up''.
BUGS
Many newer laptops do not interrupt properly on parallel printer port
events. This can manifest itself on the PE-III as poor performance when
running multiuser.
Multicast is presently handled in software, which is not good for perfor-
mance.
SEE ALSOintro(4), inet(4), arp(4)HISTORY
The xir driver first appeared in BSDI.
BSDI BSD/OS December 14, 1994 2
