I doubt you'll find much (but who knows!) the phoenix technologies board was pretty boutique, and from memory, not a great many were sold. I remember them from my ACAR mags. I wanted one so bad but didn't have the cash to send in the deposit to get a board. I see the user manual is online but no detailed info in it.
--edit: I just checked a1k.org wow, they do have schematics.. interesting.
-stu