Re: Apple //+ floppy technical info

[nathan@visi.com (Nathan Mates)]

In article <5aouuj$3kg@ren.cei.net>,  <kents@fs.cei.net> wrote:
>Where can I find technical information on the Apple // disk format?  I need
>info such as read/write gap length, format gap length, format interleave, etc.
>Any help will be greatly appreciated.

   The best reference is _Beneath Apple DOS_. Awesome reference,
though in paperback form only. [Written in 81 when electronic
publishing was a far-off dream] The Byte Works (email:
mikew50@aol.com) might have a copy, though.

   Reading up in there, standard DOS 3.3 tends to have (varies by disk
speed) about 40 sync bytes between sectors, and a longer gap at the
end of the track. 6 sync bytes after the sector's header.  As to
interleaving, Pascal disks have +2 interleaving (0, 8, 1, 9,...),
while DOS 3.3 appears to have -2 (or +14) interleaving (0, 7, E, 6, D,
5...) 4:1 interleaving ought to be fine, though I'm not sure on the
optimal.

Nathan Mates


--
<*> Nathan Mates http://www.visi.com/~nathan/      <*>
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