How to change the LPT port within CMOS

Updated: 05/21/2018 by Computer Hope

Change LPT port mode

When connecting a parallel device to a computer, such as a parallel port printer, it may be necessary to change the mode that it is using. The reason for this action is either to help prevent conflicts or allow the device to communicate with the computer in the first place. Examples of parallel port modes include unidirectional, bidirectional, EPP, and ECP.

To configure this setting in CMOS setup, find the parallel port mode and change it from its current setting to the setting suggested by the peripheral manufacturer.


If you are not sure what setting to use, we suggest bidirectional or EPP if available.

If your printer or other peripheral manufacturer is suggesting a parallel port mode that is not available, see if your motherboard manufacturer has a BIOS update to add this feature. If no BIOS update is available that extends the available parallel port modes, consider upgrading the computer motherboard.

Change LPT port

It may also be necessary to change from LPT1 (0x3BC) to LPT2 (0x378) or LPT3 (0x278). By default, all computers will assign the LPT port to LPT1. If you are changing this value either because of resource conflicts or the need for addition LPT ports, change the setting to manual in the CMOS setup.

Parallel port