serial port twain driver help please

I have a very old Pretec DC-600 (.3 MG resolution) that I was about to
discard, when I fired it up and saw a few photos on the camera that I'd like
to download. I downloaded the latest Twain driver that interfaces with my
PC via the serial port. The XP driver install went fine. I have the camera
powered up and cable plugged into the camera and PC via the serial port, but
I can't get any software to start or the system to recognize that there is
something plugged into the serial port. When I view the Twain help files,
it sure makes it look like there should be some application, but I can't see
where or how to select or start an application. I did notice that when I
installed the Twain driver, the only option available was USB, which is not
what this camera uses. Can anyone help straighten me out to help me
download these pics so I can get rid of this camera forever. Thanks,

Joe
joemagiera at ameritech dot net