TP 701C Modem As Serial Port?

[Jim Biggerstaff <jimb@infi.net>]

I've recently purchased Delorme's Tripmate GPS receiver and Street Atlas
4.0 for use on my TP701C.  Briefly, this receiver plugs into the serial
port, receives data from the GPS satellite constellation and shows your
position on a moving map on the display. It works quite well.

To use the serial port, of course, I need to attach the port replicator,
which makes things just slightly awkward.

Is it possible to configure the internal modem to work "in reverse" as a
serial port?  If possible, this would require some sort "phone plug to 9
pin serial" adaptor.

Or, as a good Plan B, are there PCMCIA serial cards available?

Thanks for any info.

Jim