Extracting CDOS and CP/M) files

Fred Cisin cisin at xenosoft.com
Thu Oct 11 12:58:08 CDT 2007


> > CDOS had one or more bytes in the first physical sector of the disk to
> > identify which format.  There ARE multiple (user modifications?) variant
> > formats that may have the same ID byte(s)!

On Thu, 11 Oct 2007, Dave Dunfield wrote:
> Anyone have more info on this? - One of my main problems is determining
> exactly what format these disks are in.

It might be stored in the first sector, or it might be known only to the
OS.
On a functioning CP/M 2.x? machine, STAT DSK: gives some of the
parameters.

> Does each entry represent a cluster?
Yes, each of the numbers in the block list represents a "cluster" (which
is the MICROS~1 word for a block)  Each OS company seems to have had their
own unique word (like "standards") for an allocation unit.

Remember that CP/M calls a 128 byte record a "sector" disunirregardless of
how many there are in each physical sector.






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