The HandSpring VISOR is a clone of the PALM-Pilot PDA.
From /usr/src/linux/Documentation/usb/usb-serial.txt:
HandSpring Visor USB docking station. There is a webpage and mailing lists.
Handspring VISOR Platinum serial port is tunneld through USB, so load usbserial.o with modul parameters vendor=0x82d product=0x100 (usbmgr.conf) USB is made active by starting the HotSync synchronisation per: pilot-xfer /dev/ttyUSB0 -b -/visor/