Re: please help--tracks, sectors, VTOC, and disk geometry

[Mark Percival <mark@syndicomm.com>]

jutland1916@hotmail.com wrote:

I can answer a couple of these.

>I have a disk image whose VTOC indicates that the last allocated track
>was 22, moving inward ($16, $01), yet there is good data beyond that
>(at tracks 33-34). How can that happen?

That is probably a reference to hexadecimal 22 which is decimal 34.  This
gives your 35 tracks since the original number is zero referenced.

>Why are the VTOC and Catalog sectors always at track 17? Is there a
>mechanical reason for this, something related to the position of the
>read/write head, given that it's the middle track of the drive?

Middle of the drive is the reason.  Track 17 is referenced often so putting
it in the middle of the disk reduces the movement of the disk arm.

Mark R. Percival - RTC Host - Syndicomm Online Apple II Forum
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