Date   : Tue, 30 Mar 2004 23:13:41 +0100
From   : "John" <blip@...>
Subject: Re: Watford > Acorn DFS

Thanks for the help Sprow; I would be interested in learning more about the
DFS clones - this is the first I have ever heard of such a thing.

I had wondered if I should just try a PC/BBC disk writing program to produce
Replicas, but on swapping my Masters 3 1/2 " disk for the PC one as an
experiment, the disk simply spun with no result. I understand this may be a
physical problem with the drive design as much as the controller?

I was interested in the thread about IDE interfacing, but that seems to have
gone quiet.

Apologies if the group has seen all this stuff before, but I have read quite
a lot, from emulators (thanks Tom - brilliant work!) to Scart>RGB cable
design and it is going to take me soooo much time to get back into it all.
(I only got as far as simple 6502!)

Best wishes

John


-----Original Message-----
From: Majordomo List Manager [mailto:majordomo@...] On Behalf Of
Sprow
Sent: 30 March 2004 19:01
To: bbc-micro@...
Subject: Re: [BBC-Micro] Watford > Acorn DFS

Hi,

> Would I be right in saying that I could fit a Watford DFS ROM to my 
> master, having *unplugged the other DFS/ADFS present
> and thereby read my old 51/4 double density Watford disks?
>
> I have a Master 128 at present with a 31/2 drive and would like to 
> transfer my old beeb b (watford) 5 1/4 disks to 3 1/2 " on the Master 
> (Acorn DFS).

I'd be almost 100% certain that this wont work as the Watford DFS will
expect to find an 8271 disc controller (like the BBC micro has).
You might have better luck looking for one of those DFS clones which claim
to be able to read the Watford discs, and which also work with a 1770.

The added confusion will come in that the Master 1770 interface is in a
different place in the memory map and the control register is layed out
differently too: so even that might not work.

When writing DOSFS I decided to attempt to detect which machine I was
running on, choose the base address and register layout based on that, then
select the appropriate NMI handler based on that,
Sprow.