Date   : Sat, 06 Feb 1988 16:14:33 PST
From   : Bridger Mitchell <bridger%rcc@rand-unix.ARPA>
Subject: DosDisk kit version

The "kit version" of DosDisk requires writing and assembling an
overlay for interface to the user's bios.  The bios must have
table-driven logical and physical disk format parameters, so that the
overlay can, when DosDisk is loaded, set or install the MS-DOS format
parameters IN THE BIOS.  (Later when DosDisk is unloaded, the a
different entry point in the overlay must restore the default format).

More simply put, you have to be able to set the bios, somehow,
so bios-read and  bios-write calls will function correctly after
valid track and sector calls have been made.  "Old-style" bioses, with
disk parameters hard-wired into the assembly code, don't normally
support MS-DOS format; "modern" bioses provide some type of
table-lookup for the parameters, and a method of altering or
selecting the table values.

The kit version is not recommend unless you have advanced Z80 assembly
language experience and technical knowledge of your bios.  The
appendix of the user's manual lists the overlay specifications, and
the kit includes a sample overlay.

BTW, DateStamper is NOT REQUIRED for DosDisk, although they work in
tandem very nicely.

--bridger mitchell


End of INFO-CPM Digest
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