Date   : Mon, 10 Sep 2007 01:05:35 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: Acorn Z80 2nd processor

>Message-ID: <20070907090104.81d2myri3ow0gok4@...>
 
Dethmer Kupers <dkupers@...> wrote:
> >> I just acquired an Acorn Z80 2nd processor for my beeb, including
> >> all books, floppies and even the keystrip.
 
Keystrip? Any chance of posting the details?
 
> > I suppose the first thing to be sure of is, is the Beeb working ok with
the
> > 3.5" drives? You didn't say which 'Beeb' is in use: BBC B or BBC Master?
> It's a BBC B. Everything (BBC, drives, GoMMC) is working like a charm.
 
I've used Z80 second processors on Beebs and Masters without
problem, both with 5.25" drives and 3.5" drives with no problems.
 
> > At least model B needs a patch for DFS when using 3.5" drives. Have you
> > checked normal DFS operations without CoPro?
 
I've never needed DFS 1.21 when using 3.5" drives under CP/M. The
CP/M BIOS does several retries when calling OSWORD &7F, so that
probably gets around the problems.
 
One thing I /have/ notice, though, is CP/M doesn't like being booted
with NET selected. I have to do Ctrl-D-Break to start up correctly.
 
> I've got the BBC/drives for 2 years, no problems at all.
> What's the patch for 3.5" drives? Software or hardware?
 
See FixDNFS at http://mdfs.net/Filing
 
> >> Can anybody shine some light on the fact that the Z80 goes into HALT-
mode?
> > Not sure though that an DFS issue can halt the Z80?
> No idea. The fact that the ROM of the Z80 and the image I got from
> internet are not the same is not giving me a warm feeling;).
 
The ROM image on my website was saved 'live', so it has a '*SAVE Z
F000+1000' string overwriting a bit of 6502 code in it. I've just
uploaded a copy created by plugging the ROM into a ROM socket and
reading it raw, to http://mdfs.net/Software/Tube/Z80
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
There are three food groups: brown, green and ice cream.