HP Prime/Linking Protocol

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< HP Prime
Revision as of 10:06, 16 August 2013 by Debrouxl (talk | contribs) (Add initial firmware reflashing analysis)
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This page aims at providing information about the linking protocols of the HP Prime.

The TI-Nspire uses vendor-specific class and proprietary protocols which require specific drivers; the Casio Prizm uses MSD, and the HP Prime uses standard classes as well. Standard classes which do not require extra driver installs are a boon to users.

High-level USB behaviour

"Normal" mode

In normal mode, the Prime exposes itself as a Human Interaction Device (HID). That's a standard class, with built-in drivers in pretty much any USB-supporting OS, aimed primarily at mice, keyboards and joysticks; lots of manufacturers (ab)use that class for other purposes.

Click to see the USB descriptors dump : Details anzeigen


Reflashing mode

In reflashing mode, the Prime exposes itself as a Mass Storage Device (MSD), another standard-class with built-in drivers.

Click to see the USB descriptors dump : Details anzeigen


Lower-level USB behaviour

Reflashing mode

Here is an analysis of the raw USB data for an upgrade to 0.30 firmware from 2013/08/09, captured by someone else.

Tools: USBpcap on Windows for capture; Wireshark and hte on Linux for interpretation.

Additional information: Wikipedia: SCSI_command‎ and pages linked from that one.

Details anzeigen