BT(4)

NAME
bt - BiTronics parallel device driver

SYNOPSIS
mknod -m 660 /dev/bt0 c 29 0
mknod -m 660 /dev/bt1 c 29 1
mknod -m 660 /dev/bt2 c 29 2
chown root.lp /dev/bt?

DESCRIPTION
The bt device driver is a replacement for the standard parallel printer driver lp. It enables the use of the status readback feature from printers equiped with a so called BiTronics (bi-directional Centronics®) interface. The BiTronics device driver bt for Linux implements the necessary communication protocol on the host side. Most - if not any - of Hewlett-Packard's LaserJet® 4 series printers are equipt with such a BiTronics interface. In the direction host to printer the interface is compatible with a normal Centronics interface. In addition, the interface can be switched to a printer to host mode. In this mode the host is now able to read back printer status information etc.

I/O CONTROL
None (currently).

FILES
/dev/bt*

EXAMPLE
Assuming your LaserJet 4x is connectet to the second printer port /dev/bt1, then

    echo -e "\033%-12345X@PJL" >/dev/bt1
    echo "@PJL INFO VARIABLES" >/dev/bt1
    sleep 2
    cat /dev/bt1 | more

will deliver a list of the current values of the printers' variables.

SEE ALSO
chown(1), mknod(1), lp(4)

COPYRIGHT
Copyright (C) 1994 by T. Weidenfeller You are free to copy, modify and distribute this material as you see fit, and to use it for any purpose, provided this copyright notice and the warranty disclaimer are included without any modification in all copies and modifications. You have to mark all modifications clearly and you are also commited to give propper acknowledgment of the original source if you include this material or parts of it in another software.

WARRANTY
The BiTronics device driver and the accompaning material is a free sample of no commercial value. It comes without any warranty: THERE IS NO WARRANTY OF ANY KIND WITH REGARDS TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MECHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. The author shall not be liable for errors contained in the material or for incidental or consequental damage in connection with the furnishing, performance, or use of this material.