>
>Jim,
>
>How can a portable PC with one com port (has a usb port too) with airmail
>2000 version 2.16, that is connected to a PTCIIe on that com port (works
>great!), hook up a GPS receiver that also uses a com (serial NMEA) port?  Is
>there any way a portable PC can have two com ports?  Can the usb port be
>used as a com port?  This application is for my sailboat.  How do you do it?
>
>73 de K5GP, Gene
>

Gene,

Assuming the computer is fairly recent and the USB ports work properly,
the best option is to add serial-ports to the USB port. (There is a USB
test which can be downloaded from www.usb.org, click the "Shopping for USB"
tab on the left and then look for the "USB Evaluation utility").
If more than one serial-port is needed then Digi (ex-InsideOut Networks)
makes 2-, 4- and 8-port USB-serial adapter boxes called "Edgeport/2" for
the 2-port (around $135 at buy.com), Edgeport/4 ($235) or "Edgeport/8"
($360). Also see www.ionetworks.com, also available from CDW or buy.com.
These are self-powered from the USB port and work well. We use an Edgeport/8
on our development computer.  If you only need one port, the simplest choice
is a USB-to-Serial port "dongle", a 6" cable with a USB plug on one end and
a 9-pin male serial-port connector on the other.  The one that I have heard
good reports on is the Xircom "PortGear" (ex-Entrega) USB to 9-pin Serial
converter (p/n PGSDB9), about $38 from CDW (www.cdw.com) or buy.com. Belkin
makes single-port serial-port adapter which is relatively bulky (F5U103 for
about 65 from buy.com).  There are others, but these are the ones that we've
had good experience with or heard good reports on. My #1 choice would be the
Edgeport, quite a few have been used with no problems yet. If you plug
everything into the Edgeport box, then there is only one cable to unplug in
order to put the computer away.  Consider adding extra ports, things to
consider besides the PTC-IIe are the GPS cable for Airmail's position-
reporting, a second cable from the GPS for a charting program, and perhaps
remote-freq control for the SSB radio if it is compatible.  Any of these
devices create new COM-ports, whatever the next COM-port number is
available after the modem, virtual IR ports, etc. Windows Control Panel/
System/ Device manager can be used to find out the port# if all else fails,
check under Ports.  I hope this helps.

Jim, ke6rk@winlink.org