VAutomation Inc. VUSB inside pv2!?
http://web.archive.org/web/20010115230500/www.vautomation.com/vusb/vusb.html
Very interesting. Note that the pv2 uses a 48Mhz crystal which is also called for in the VUSB article.
Now to get some source code for it or datasheets.
