I'd like to report that I found the mother lode(s) of technical information for the operation of USB devices. I have learned so much in the last few hours thanks to the new found info. The breakthrough came when I stopped searching for 'usb balanced feedline' and started searching for 'usb differential data transmission'!!!! What a difference a few words make in an internet search attempt! Tomorrow's a new day, but at least I'll retire knowing that documentation is out there and just waiting for me to find. Regards, Art --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .