Psion Teklogix Netbook Pro User Manual

8.2.5  Fax/Modem On COM 1/2/3/4

If you have a Fax/Modem using COM Port 3 or 4, and ActiveSync on COM 1 or 2 
(or vice versa), you may have trouble when trying to connect with the NETBOOK 
PRO.

Because of the way a PC handles COM ports, COM1 and COM3 are ‘linked’, as are 
COM2 and COM4. Specifically, they share the same Interrupt Request (IRQ). 

In practice, this means that if you have a modem on COM3, it may conflict with the 
NETBOOK PRO on COM1 (and the same applies for COM4 and COM2). The 
solution is to try using ActiveSync on a different port or to assign a different IRQ. 

You can check the COM port properties by following the steps above to get to the 
Device Manager page and double-clicking on the COM port.

Again, if you are in any doubt about whether you are able to do this safely, you 
should contact the person or organization that supports your PC.