All,
Much to my amazement, I actually remembered how this all worked!
In brief: A collection of Applicard drivers, CP/M utilities and
ProDOS utilities that boots and runs the PCPI Applicard (or Freed Z80
card) directly under a live ProDOS-8 environment.
Once you stage into it, it's possible to boot directly from a hard
disk, quit to ProDOS as you would from any SYSTEM application and
transfer files easily back and forth between CP/M and ProDOS.
This suite was a by-product of early CardZ180 system development
(CardZ180 only works this way and did so out of the box). We didn't
offer it standalone in order not to hurt sales. Now, there's no good
reason to sit on it.
I'm going to spend some quality time writing up a quick how-to and try
to get it posted in the Yahoo Apple CP/M group within a few days.