An example of how this is not needed can be found on the Program Writer
disk. Boot the disk, and it will start in ProDOS (1.1.1). Select "Switch
to DOS 3.3", and lo and behold it switches to DOS 3.3! Extra-K had all
the necessary tools to do this. I think it marked the first half of the
disk used in the DOS 3.3 allocation tables, and the second half used in
the ProDOS allocation tables. There were directories for both OSes, and
DOS.SYSTEM loaded DOS 3.3 from ProDOS.
My idea would be to replace DOS.SYSTEM with a PRONTO.SYSTEM, ZDOS.SYSTEM,
TDOS.SYSTEM or ESDOS.SYSTEM which would load a faster DOS.
Is the EXTRA-K disk on Asimov? or do you have a link to one of these hybrid
disks? or the ORIGINAL dos.system ?
Red