Looking at the June 83 ad for the Hyperion I noticed that it has 320K drives
instead of 360K. If I remember right the 320K format is 7 sector not 8 sector
drives.
I propose an experiment even though I too, believe it takes a special version
of DOS. Get an old PC and format a DOS disk at the 320K format using ver 2.11.
Transfer the system and see what happens.
Paxton