Ernie,
Yes, "That Ernie". :-) Long time no talk.
You can get a USB to serial adapter and use that. The Classic Pronto FAQ has some notes. The key thing for the Pronto is that it is connected to the first COM port.
By first, consider you have a Mouse on COM2 and then have a USB2Serial as COM4, You will need to modify the driver config to make USB2Serial show up as COM1.
