Defining Disk Image Dump Standard

From: CLASSICCMP_at_trailing-edge.com <(CLASSICCMP_at_trailing-edge.com)>
Date: Sat May 27 16:52:19 2000

>> This is a good start. The header should include a byte that contains a
>> flag indicating the status of the sector (good, bad, etc).

>Other things that are 'missing' from that header are whether the sector
>is single or double density, what sort of Data Marker came before it
>(some TRS-80 disks use strange data markers, and just about all TRS-80
>M1/M3/M4 OSes use deleted data markers on the directory track).

Then there are some *real* oddballs, such as disks with 18 or 12 or 9
bits per byte.

It's very, very common for double-density CP/M disks to have the boot
sector - and in some cases the first few tracks - in single density.

For these odd formats, I just record the waveform from the head
for each track for a couple of revolutions, just to make real
sure that I'm not missing anything :-).

Tim.
Received on Sat May 27 2000 - 16:52:19 BST