Date   : Tue, 22 Aug 2006 20:49:34 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: Hard disk backup - another challenge

>Message-ID: <001f01c6c5d4$41860a80$0301a8c0@...>
 
"David Harper" <dl.harper@...> wrote:
> Andrew Benham wrote:
> >
> > Ah, that'll be the 10 MegaByte $.DOS.DRIVE_C file then - i.e. the
> > file used by the 80186 Co-Processor to provide the DOS+ file system.
> > That DOS+ file system is nothing like full, so there's loads of
> > sectors which I don't need to backup.
> 
> ADFS sees the whole of $.DOS.DRIVE_C as a single file and has no way of
> understanding its contents. A simple ADFS back-up is bound to transfer the
> whole of this big "file" entire.
 
SerLink at http://mdfs.net/Software/Comms manages quite good
speeds through direct access to the hardware.  It sends the data
in one huge chunk, so a file full of repetative data takes the
same time as a file full of random data. It would be worth
updating it to send the data in packets with some form of
compression, such as "this packet is all zeros".
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
BBC BASIC for the Sinclair Spectrum - http://mdfs.net/Software/Spectrum