Date   : Tue, 19 Jan 1999 08:58:41 +0100
From   : "Mark Usher" <marku@...>
Subject: Re: Backup BBC Hard Disk to PC ??

Hi

> Having turned the hard disc on my BBC Master on for the first time
> in years, and discovered some verify errors, I reckon I ought to
> back it up before I go too much further.
An excellent idea. You are to be commended on your foresight.

> It struck me the other day that the BBC Master with its 20M hard
> disk is sitting next to a PC with a 6.4G disk, which could hold a
> 20M backup image and not notice it!

> Has anyone come up with a clever scheme to backup a BBC hard disk
> to a PC ??

Right. I have been thinking about this myself recently. There is a program
to connect a BBC / Master to an archimedes and use it's hard drive but
that's not quite what we need.

There are a couple of options.
1) You could remove the hard drive and attach it to an MFM/RLL inteface in a
PC. This has a few problems. Mostly that the BBC drive is formatted to 256
bytes per sector whereas a PC expects 512 bytes per sector. I have a few
programs that *might* be able to handle this, but I'll have to experiment a
little. This would obviously be the fastest way.

2) Using a Xfer program you could transfer the entire disk, sector for
sector over the serial port to the PC. This would probably be the easiest
method to implement but would be very slow. Probably an overnight job. eg. I
have two hard drives, 1x80MB, 1x20MB.
I'm not sure how this would cope with a file server drive as they are not
ADFS. It all depends on how the Beeb handles the sectors that are retrieved,
it could be ok though.

3) The above 2) could be used, but using a parallel Xfer from the User Port
to the PC's printer port "laplink" style. I've just started playing around
with this and it looks quite feasable. Much better data transfer could be
acheived.

4) A neat idea would be to make a hardware interface to plug the PC into the
1MHz bus and use it rather like OPUS implemented their RAM drive. Could be
an interesting project, bit above my capabilities though.

So, as a quick answer, I've emailed Stuart to ask him if it is possible to
adapt his pcXfer program to do this. I'd like to write a program to then
manipulate the resulting image, or maybe Laurie Whiffen might like to
implement this in his BBC Explorer program. You could then transfer the new
image back :-)

Maybe someone else has some other ideas ?

Mark Usher
marku@...