System Administration Guide
Chapter 4, Managing printers and print jobs

Parallel printer is slow

Parallel printer is slow

If your parallel printer prints abnormally slowly, verify that the configuration settings are correct. In particular, printing can be slow if the port is configured for the right I/O address, but the wrong interrupt vector. To check and change this setting, see ``Adding and configuring parallel ports'' in the SCO OpenServer Handbook. To change the interrupt vector for a slow port, remove and reinstall the parallel port with the same I/O address but a different interrupt vector (5 or 7). Relink the kernel in the SCO OpenServer Handbook, reboot the system in the SCO OpenServer Handbook, and see if the port is still slow.

If the parallel ports are configured correctly and printing is still slow, your parallel port may not be capable of generating interrupts. In this case, you can try setting up polling for your printer port.

If your line printer is taking about four seconds per line, the printer may be deselecting itself after receiving each line of text and then reselecting. In this case, you can modify a kernel parameter to change this behavior.