Dave Smith Instruments Prophet REV2 Mode D'emploi page 142

Using USB
The Prophet Rev2's USB 2.0 port enables bidirectional MIDI commu-
nication with a computer. A MIDI interface and MIDI cables are not
necessary, just a USB cable. The Prophet Rev2 is a Class Compliant
USB device. That means it does not require any additional drivers to be
installed to communicate with a Mac or Windows computer. The Prophet
Rev2 transmits and receives MIDI data via USB, but does not transmit
audio.
MIDI In and USB should not be used at the same time, as overlapping
messages from different sources may cause the Prophet Rev2 to respond unpredict-
ably. MIDI Out and USB can be used at the same time and transmit the same data.
USB Notes
Under Mac OS X, "Prophet Rev2 Keyboard" will appear as a MIDI port
MIDI Setup utility (typically found in Applications/Utilities).
the "Found new hardware" alert appears and it is automatically installed
as "Prophet Rev2 Keyboard."
In Windows, if you unplug the USB cable and plug it back in while a
program has the Prophet Rev2 port open, you may have to resync. That
usually means going to the Prophet Rev2 Keyboard Properties — in the
Windows Device Manager under "Sound, video, and game controllers"
— and clicking OK. If Prophet Rev2 Keyboard is no longer listed in the
Device Manager, power the Prophet Rev2 down and back up again while
it is connected via USB. It should be detected on power up.
Prophet Rev2 User's Guide Using USB 67