Re: DOS 3.3 VTOC Puzzle: Precise Meaning of "Last Track Allocated"

[Andy McFadden <fadden@fadden.com>]

Andy McFadden <fadden@fadden.com> wrote:
> Read the description of the code at $B244 in Beneath Apple DOS,
> specifically the code at $B272.  It references $B3EB, which holds the
> "last track allocated" from the VTOC.

BTW: I don't have DOS memorized.  I booted the DOS system master in
AppleWin, did a "BSAVE DOS,A$9600,L$2A00", opened the "DOS" file in
CiderPress (which defaults to a //e-style monitor listing), and copy &
pasted that into a Notepad window.  I skimmed through Beneath Apple DOS
to find where the VTOC was kept, then did a text search through the DOS
listing to find the locations that referenced the "last track allocated"
field (there are three: one in the INIT code, and an LDA and a STA in
the code I mentioned earlier).

This approach doesn't always work, but it's quick and easy.

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