Did you have any joy with the FTDI Vinculum? ... I'm just starting to interface a 89CV51 to the VDIP1 module for mass storage and wonder if you have any words of wisdom.

yes, It is (now) a joy.

word of 'wisdom':
Do not believe the documentation re what 'comes back' write yourself a program that will send what you 'patch in' and SEE what coms back. I wrote a ton of code that believed the manual in this respect and had to revert to the above and then start over. Make sure you try all combinations e.g. when reading a directory try blank stick, stick with and without volume label (btW there is a bug if the label is 9 characters which a bug in Windows allow) root directory, directory one and more levels up ,,,,,, You WILL be surprised comparing the responses with the manual.

If in the process you run into specific problems, I'll help as far as copyright rules allow (I do not own the copyright on what I do).

Erik