Re: Suggested change to add volume numbering to .dsk disk image files

["Charlie" <charlied@NOSPAMbboard.com>]

Thug <mhurwood@dingoblue.nospam.net.au> wrote in message
news:39aa4da7$0$780$7f31c96c@news01.syd.optusnet.com.au...
> "Joseph Oswald" <jaoswald@is06.fas.harvard.edu> wrote:
> >
> > > Plus, with DOS 3.3 and compatible formats, could the emulator not pick
> up
> > > the volume number from the VTOC? (Track $11, Sector $0, Byte $6. I
don't
> > > know if there's a similar record in ProDOS.) Protected disks or disks
> with
> > > their own custom DOS are still a problem, of course...
> >
> > I think that the volume number in the VTOC actually is *unrelated* to
> > the volume number encoded in the sector address fields. I seem to
recall,
> > perhaps in the _DOSTalk Scrapbook_, some discussion which indicated
> > that DOS 3.3 itself made no effort to properly initialize this value
> > before formatting a disk.
>
> Never heard of that before! It's certainly not mentioned in "Beneath Apple
> DOS", which is where I get almost all my knowledge of DOS internals.
>
> Just goes to show, even 20 years later I'm still learning stuff about the
> Apple ][.
>
>
> Michael
>
>

"Beneath Apple DOS", 5th printing, March 1983, page 4-2, shows byte 6 of the
VTOC contains the volume number (1-254).

Charlie