Re: DSK format specification

["Michael Pender" <mpender@hotmail.com>]

Andy McFadden <fadden@fadden.com> wrote in message
news:lr0Qa.1241$dk4.53908@typhoon.sonic.net...
>
> Track 0, sector 0, byte 0 starts at byte 0 of the file.  This is because,
> for all possible sector skews, sector 0 is always in the same place.
>
> Track 0, sector 1, byte 0 could be in one of three different places.
> That's the difference between .PO, .DO, and Copy ][+ .IMG.  If there
> were a CP/M disk-image utility you'd have four possibilities.
>
> A DOS utility will read sector 0 through sector 15 and write them out
> in that order.  A ProDOS utility will read block 0 through block 7 and
> write them out as 512-byte blocks.  Unfortunately, block 0 is track 0
> sector 0 combined with track 0 sector 2, *not* track 0 sector 1.  This
> means that disk images created with DOS RWTS-based utilities are
> different from images created with ProDOS utilities like ShrinkIt.

I remember that back-in-the-day (BITD?) there were disk utilities that
changed the interleave between DOS disk sectors to speed up file transfer.
That is, physical sector 0 and logical sector 0 are always the same, but
physical sector 1 and logical sector 1 could be different.  Is this a
similar problem?

- Mike