Date   : Fri, 24 Jun 2005 10:22:22 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Re: Watford Electronics DFS

Andrew Benham <adsb@...> wrote:
> Jonathan Graham Harston wrote:
> > No, there is Watford DFS for the 8271 and Watford DFS for the
> > 1770. I was once instructed that WDFS 1.4x was 8271 and WDFS 1.5x
> > was 1770, but another poster said that was incorrect.
> 
> I've a nagging feeling that Watford's 1770 disk upgrade wasn't
> compatible with Acorn's - or maybe there were two versions of
> the Watford 1770 disk upgrade, and only the later ones were
> compatible.
 
You're right. The earlier WDFS addressed the 1770 in a different
location to Acorn. From my cursory examination of the
disassemblies I wasn't able to work out which WDFS versions
addresses the 1770 at what address. Also, version 1.54 was the
only one I had to hand, and it uses Acorn addressing ;)
 
> I picked up a Watford 1770 board somewhere years ago, but
> never used it, and it went to a new home.
> 
> If anyone knows the answer, I'd be happy to include it on
> my "gory details on disk controllers" page
> (http://www.adsb.co.uk/bbc/disk_controllers/)
 
If I come across the information I'll let you know. Otherwise, if
anybody had Watford DFS 1.5x earlier than 1.54 I could disassemble
it and work it out.
 
I have gaps in my collection. I have: 1.10, 1.30, 1.43, 1.44 and
1.54T.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
HADFS System Resources - http://mdfs.net/Software/HADFS