System Administration Guide
Chapter 4, Managing printers and print jobs

Setting up polling

Setting up polling

To speed up printing on your parallel printer, you can alter the way that the hardware and the printer driver communicate. The parallel printer driver can be made to ``poll'' a parallel port so that the driver does not rely on interrupts from the parallel port. 

NOTE: When the printer driver polls a parallel port, you may experience a drain on system resources.

To set up polling for a parallel port or parallel printer, you must create a polling device file and reconfigure your printer to use it instead of the standard device. Use this procedure:

  1. Bring the system into maintenance mode. See ``Using the shutdown command line'' in the SCO OpenServer Handbook.

  2. Note which parallel printer ports are configured. Enter:

    /etc/hwconfig -h

    You should see output like this:

    parallel 0x378-0x37A   07    -    unit=0
    where unit=0 refers to lp0.

  3. Configure a special device file for the printer. Create a file called pa (if it does not already exist) in the /etc/conf/node.d directory containing one of the following lines:

    For lp0: pa lp0p c 64 bin bin 600
    For lp1: pa lp1p c 65 bin bin 600
    For lp2: pa lp2p c 66 bin bin 600

  4. Enter these commands to reconfigure the kernel to recognize the new device:

    cd /etc/conf/cf.d
    touch /etc/.new_unix


  5. At the prompt to rebuild the kernel environment, enter y.

  6. Reboot your system. See ``Using the haltsys command'' in the SCO OpenServer Handbook.

    When you enter multiuser mode, the new polling device is in place.

  7. If you are using the print spooler, you must now inform the spooler of the new parallel poll device.

    In the Printer Manager, select Connection from the Settings menu. Do not select a standard parallel device name. Instead, select or enter either /dev/lp0p, /dev/lp1p, or /dev/lp2p.