Thanks to Erik for the tips on using this device.

So I got a VDRIVE2 and managed to make it work OK with the SPI interface. Actually, for me, writing the "non-standard" SPI code was not bad at all compared to the other issues, like paying close attention to responses to commands, etc.

I have only read and written small simple files in the root directory so far, and expect to need to do more research if I go further.

The toughest part was organizing the documentation from the VDRIVE, the VNC1L, and the Viniculum Firmware Users Manual, and figuring out which parts of each I needed to know to make the VDRIVE2 work.

Some of this is because I just bought a VRIVE2 and did not do any particular research on the chip or the concepts related to it.

For anyone planning to give this device a try, I suggest hooking it up in UART mode and use a terminal program to play with the commands. Yes, you will need RS-232 drivers like a MAX232 (which the datasheet does not tell you.)

CTS must be asserted (if simply typing in commands) or controlled by the RS-232 hardware if communication is fast.