Date   : Sun, 22 Jan 2006 21:32:40 GMT
From   : Pete Turnbull <pete@...>
Subject: Re: eBay What is this?

On Jan 22 2006, 20:31, Andrew Benham wrote:
> Jonathan Graham Harston wrote:
>
> > Unfortunately, the ADFS OSWORD &72 sector commands refuse to work
> > if a drive has not been mounted.
>
> Err, are you sure about that ?  If so, then it would be impossible
> to ever format one's first disk under ADFS.
> Maybe you need to do an "F BREAK", to start ADFS with no drives
> mounted ?

Or type *FADFS, of course, which amounts to much the same thing.

Even reading and writing a sector does not require the disk to be
mounted (for example, when formatting, you have to write the disk map
to the drive before you can mount it).

> > Doublely stupid, ADFS refuses to
> > MOUNT a drive if it does not have an ADFS filesystem on it.
>
> No, that's sensible.  MOUNTing a disk tells the user (and the
> file system calls) that the disk has a valid file system on
> it and is ready to be used.

Agreed.  Mounting makes no sense otherwise; that's the whole point of
the operation -- to make the OS aware that disk is available.  The same
scenario is typical of other operating systems too.

> > The only way to do it is to feed SCSI commands directly to the
> > hardware, which, at the moment, is a bit beyond me.
>
> Osword &72 is essentially Acorn's wrapper around the SCSI command
> block.

And the FDC commands.

> Maybe my memory is playing me up, but I'm sure that you can use
> Osword &72 on an unmounted disk.

Of course you can.  That's how you issue the commands needed for
formatting, for example -- not just the format-track command but all
the Mode Sense, Mode Select, seek, verify and other commands used by
non-Adaptec controllers.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York