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by Stuart Udall and Martin Thompson

Many printers use a special parallel port configuration known as bi-directional. These machines will not work properly if a bi-directional cable is not used; also, they will fail if the printer port is not configured correctly. When faced with one of these machines that's "not printing", particularly if it is new, check the cable, and then check the parallel port setup.

There are two places where setup can be done: in the PC's BIOS, and in Windows Control Panel. Do the BIOS first. Windows may reconfigure itself after changes are made to the BIOS settings. Change the BIOS with care - the PC may do funny things if these settings are set incorrectly. Take notes if necessary.

Bear in mind that it will be a particular combination of settings that gets the hardware working. Given that there are two settings in Windows (ECP and Standard) and at least two settings in the BIOS, this is at least four combinations of settings that need to be tested. Be methodical!

Once the PC comes back up, try a test print: if it still doesn't print, uninstall the printer driver and reinstall it.

cabling to-be-avoideds

• standard or replaced printer cables - use the supplied cable only (which may be proprietary, also some are simply IEEE 1284P)
• older parallel ports, such as those found on older models from Compaq, Toshiba, and Acer
• old software - use new drivers, and preferably Windows 98SE
• daisy-chained parallel connectors (such as ZIP drives and scanners)
• parallel switch-boxes

checking/changing the parallel port configuration (BIOS)

Usually the BIOS has a key (such as DEL) which the user must press during POST in order to enter the BIOS setup. POST occurs right up until the PC beeps and says "Starting Windows 95..". Each BIOS is different, but we have had limited success using the following procedure on AMI BIOS and Award BIOS:

1. restart the PC
2. press the BIOS entry key (such as DEL) before the PC beeps and says "Starting Windows 95.."
3. use the arrow keys to select Peripheral Setup (or Integrated Peripherals, or Advanced), press Enter
4. use the arrow keys to select Parallel Port Mode, press Enter
5. use the PgUp/PgDn or +/- keys to change the setting. The one currently recommended is Bi-Directional. Other settings may include SPP, Standard, Normal, EPP, ECP and EPP + ECP. Try them in this order.
6. press Esc to get to the main menu
7. press F10 to save and exit, Y, Enter
8. cut power to both the PC and printer for about 10 seconds
9. power-on both devices

checking/changing the parallel port configuration (Windows 9x)

• Start.. Settings.. Control Panel.. System.. Device Manager.. Ports..
• if the port is set to ECP, change it to Printer Port LPTn; if it is set to Printer Port LPTn, set it to ECP. If this doesn’t fix it, change it back again. NON-ECP is the setup currently recommended.
• the procedure for changing the port setup is below:
  1. click on the ECP port entry in the ports list
  2. Properties.. Drivers.. Update or Change Driver..
  3. if driver wizard appears, do NOT search for the driver - select manually locate
  4. click Next..
  5. a two panel window appears, mostly empty, ECP Printer Port in left-hand panel
  6. click Show all hardware..
  7. select "Printer Port LPTn" from the right-hand panel
  8. click OK or Finish (Windows disk may be required)
  9. reboot