Date   : Thu, 12 Feb 2004 11:48:24 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: Hello, and ARM second processor

On Thu, 2004-02-12 at 09:34, Chris Jones wrote:
> In amongst the junk was something which I understand is a bit special: an
> Acorn ARM Evaluation System, which got me excited about its historical
> interest, especially as many of the projects I get involved with these days
> seem to involve ARM processors.

That's a very nice find. Out of interest, what's the serial number? I
don't think we've ever found anything that implies more than 50 or so
were made.

Strange thing to be thrown out; I would have thought all the units left
were now in the hands of private collectors.

> Does anyone have any experience of actually making one of these work? 

Bleh, it's so long since I've tried mine. I seem to remember it doing
something without any floppies though, but that was on a BBC B, not a
B+. 

I'm pretty snowed with other projects right now, but if you don't get
help from elsewhere I can dig my unit out of store and take a look at it
in a few days.

> no difference - does it require a sideways ROM in the Beeb to work?

Almost certainly not. I got my unit years ago on its own (with the
polystyrene box, but no cardboard, docs or floppies), so it wouldn't
have come with a host BBC machine - and I remember getting it to do
something. I'm sure I didn't need to find + burn a ROM for the BBC host.

Check the obvious stuff inside the unit - PSU voltages, fuse etc. 
I've got a dump of the monitor eprom if yours turns out to be toast. 

>  I wasn't
> sure what to expect, since the only comparison I've got is the 32016 second
> processor which definitely comes up in 32016 mode and refuses to run 6502
> code. I was sort of expecting something similar.

Ooh, throw that this way will you? ;-)
I keep on looking for a 32016 copro; I've got the 4MB board inside my
ACW but not the 2nd processor unit for the BBC. 

> Any clues? And if it seems it's broken, 
> does anyone have a circuit diagram?

I don't know of a schematic for them; if you find one please let me
know. And don't go throwing it out again if it's busted... :-)

good luck,

Jules