[Coco] OS-9 loading NEW WAY

[Brett Gordon]

Gene,

Yup, I believe "ofs" and "wpc" (or is it "wps"?) that Boisy used as a
pre-filesystem offset for superdriver.  This is fairly well documented
in the Superdriver docs.  Side note: this offset is a low-level
offset,  lower level than RBF.  This offset is a physical sector
offset, not logical - it is not dependent on sector size. (so don't do
any 512/256 address conversion!)

The traditional way of booting Nitros, via BOOT/REL, indeed will not
work with this partitioning.  The LSN0 reference to the file
descriptor sector would need to be added to the wpc/ofs by BOOT/REL to
work.  Unfortunately, this offset is stored in a device descriptor in
the OS9BOOT bootfile, in the RBF filesystem, in a partition... which
is circular... there's no way to reach the reference to load itself!
Hence we need a real partition table at a known location.

On a side note:

I would strongly urge anyone wanting to create a partition format, NOT
to kludge it up with combining it with Nitros's "lsn0".   I know
Nitros people are keen on tunnel-visioning, but keep in mind we have
other OS's to choose from, and soon FUZIX will be added to this list.


And on that note:

I would like to publicly thank Boisy for:
  1. Superdriver, and good enough documentation to make the above possible
  2. The fore-thought to make the low-level routines HDBDOS handle 512
byte sectors.
  3. and releasing HDBDOS to the community,  my YA-DOS wouldn't exist
without it.



-- 
Brett M. Gordon,
beretta42 at gmail.com