I also had the Datadesk 101 for the MacPlus. As I recall there was an INIT for it so you could access all of the keys. I did use it with 6.0.8

I wrote a ZBASIC routine that was able to detect every possible keystoke with it.

For the life of me I can't remember what I did with it. I must have gotten rid of it when I moved in 2001 (RATS!)