HP Visualize c360 Supplementary Manual page 25

• The HP-UX DDK has not yet been updated for USB. If you know how to write a
WSIO driver, you are qualified to write a USB Class driver. A "CDDK" (Class
Driver Developer's Kit) is under investigation.
• Many non-HID devices so far introduced for Windows PCs are using the Vendor-
Specific Class (not an encouraging development, compared to iMac, where
devices by and large are using standard Classes). Getting documentation on V-S
command sets is often difficult or impossible.
• Caution: the current National Super I/O chip used for the built-in USB does not
support isochronous USB protocol. If your device can't be operated correctly
using USB bulk or USB interrupt I/O, you'll need to rely on a PCI-USB card to
support isochronous.
• Not all audio devices require isochronous, but many of them feature multiple
devices, often of the HID Class (knobs, buttons, etc.).
USB Developer Considerations