Date   : Mon, 12 Nov 2007 08:05:28 +0000 (GMT)
From   : info@... (Sprow)
Subject: BBC B+/Winchester/2nd processor

In article <071111135502@...>,
   Jonathan Graham Harston <jgh@...> wrote:
> > Message-ID: <229560.63813.qm@...>
>  
> silvercreekvalley wrote:
> > I'm trying to set up a BBC B+ with a 2nd processor (6502) and a
> > Winchester disk.
> > 
> > I've installed ADFS (1.3 I think) and DNFS ROMs as well as the
>  
> DNFS contains DFS for the 8271, the B+ uses the 1770 controller.
> You need a version 2/B+ DFS such as DFS 2.10.

[snip]

> I'm not sure about the B+ and second processors. Does anybody know if
> DFS 2.10 contains the Tube code?

DFS 2.26 certainly does (the copy loop is at &AF13), and that's the last
version of 1770 DFS suitable for use in the B and B+. Please set fire to all
copies of DFS 2.10, it's got a problem claiming workspace that stops it
working properly when more than one filing system is installed.

In article <yJkvW6AP3$NHFwZy@...>,
   Mike Tomlinson <mike@...> wrote:
> All you need to use a second processor is a ROM with the "TUBE host
> code" in it.  The DNFS has this code.  IIRC, the code is installed at
> &0D00 if a second processor is detected.

I think you mean &400 there. &D00 is still reserved for the NMI handler - it
has to be since the NMI vector is hardcoded in ROM to &D00,
Sprow.