Disc Imaging / Kryoflux - Acorn ADFS 800KB

pete pete at dunnington.plus.com
Mon Jul 4 03:43:25 CDT 2016

On 03/07/2016 00:51, Fred Cisin wrote:
>> On 07/02/2016 02:15 PM, Peter Coghlan wrote:
>>> The original ADFS had 16 sectors of 256 bytes per track. However, it
>>> appears that more recent ADFS formats use 5 sectors of 1024 bytes.
>>> There are more details here:
>>> http://mdfs.net/Docs/Comp/Disk/Format/Formats
> . . . and the "F" and "F+" would require a "high density" drive
> (not clear from that chart, but probably 1.4M)

Yes, they do.  The rest of the ADFS formats use ordinary DSDD drives.

> I don't the the Acorn file system, so couldn't extract files.
> But reading sectors should not be a problem, although there are
> certainly SOME things that Acorn could have done that would confound an
> If the sector headers are "normal", then INT1Eh (to set the sector
> size), followed by INT13h should work.

Acorn formatter s/w doesn't write the optional "index mark" before the 
first sector so some PCs have trouble understanding Acorn disks.

Pete Turnbull

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