T42 WinXPP thinks (ancient) serial GPS is a mouse

[DaveG11th]

This may not be solvable... in fact, it may be so bizarre that answers may not be possible.

I have an old Rand McNally GPS receiver that uses the serial port for data and a PS2 plug for power. So far as I know, the PS2 plug is enabled only on the +DC pins, with no other pins connected.

When the GPS receiver is plugged in via a Port Replicator, the T42 thinks the device is a mouse, and the cursor jumps randomly everywhere.

I notice that Ultranav is apparently a PS2 device.

NT had a boot.ini file where you could specify 'nomouse' for a given COM port (in this case COM1). Is there a similar function somewhere in Windows XP Pro?

[DaveG11th]

Solved

Yes, it is bizarre. GPS serial receivers send data patterns that Windows XP interprets as a Microsoft Serial Ballpoint Mouse.

You have to boot with the GPS receiver in place, remove the receiver, then go to the Device Mananger, open Mice and other pointing devices and disable Microsoft Serial Ballpoint Mouse.