Hi,
1. DOS 3.3 rewritten as an ABI emulation layer?
[...]
If it works, it might make some DOS 3.3 stuff more readily accessible to
hard disk and 3.5" disk users.
My (surely limited) experience is that DOS 3.3 programs which don't
actively access DOS 3.3 tend to work with BASIC.SYSTEM as it occupies
the same memory area used by (non-moved) DOS 3.3.
On the other hand DOS 3.3 programs actually calling into DOS 3.3 tend
to do so on the sector level (using RWTS calls) instead of the file
level (using File Manager calls).
So the question is what you would want to emulate?
1. Emulating DOS 3.3 files with ProDOS 8 files should be feasable
(with some restrictions on file names etc.), but the question is how
useful it would be (see above).
2. Emulating DOS 3.3 sectors with ProDOS 8 sectors doesn't make sense.
3. Emulating DOS 3.3 sectors with ProDOS 8 image files makes most
sense and was therefore already done in the 80's:
http://en.wikipedia.org/wiki/DOS.MASTER
Just my two cents, Oliver