7xx updates, 1.74 and earlier from the SD site:
Update Firmware
* Insert the Compact Flash card into the 722 (if using CF upgrade method).
* Disconnect all audio and data connections, including FireWire.
* With the unit powered up, navigate to Update Software in the setup menu. It is the last menu selection.
* Following the on-screen instructions, the unit will locate the firmware file. Select update.
* Read the on-screen instructions for updating firmware.
* The upgrade process may take up to five minutes.
* If the firmware is being updated from revision 1.74 or earlier, the update process must be completed twice. The first time through updates the "boot block" to a later version. The second time applies the firmware. For updates from versions later than 2.00, this two-step process is not necessary.