Date   : Fri, 05 Aug 2005 09:39:20 +0200 (BST)
From   : Johan Heuseveldt <johan@...>
Subject: Re: Econet-Ethernet bridge

Hi Phil,

On Thu 04 Aug, Phil Blundell wrote:
> On Thu, 2005-07-28 at 21:54 +0100, Mike Tomlinson wrote:
> > In article <Marcel-1.53-0727182555-0e8xSBG@...>, Johan
> > Heuseveldt <johan@...> writes

> > > Make sure you have the correct one. Early Master version didn't have
> > > the contention hardware on it. This was done in software by comparing
> > > the bytes sent with the bytes read back. Very soon though, the boards
> > > has the same contention hardware on it, as the BBC-B has.
> > 
> > Telling the difference is easy.  The version of the module without
> > collision detection has 4 chips, the one with has 6 chips.
> 
> Does anybody have a copy of the schematic for the board with collision
> detect?  I just checked the one that I had here, and it seems to be the
> older version.

Yes, quite odd. IME it's always that older drawing popping up.

As far as I understand, the switch back to hardware collision detection
(as in the BBC) was made very quick, so boards without that hw aren't
found. Well, not easy I mean. But the situation with the drawing looks 
the oppposite: the correct one seems hard to find, but no lack of the
wrong one.

Try to obtain a BBC-B drawing, as that's the hardware in use, although
line drivers are of older type. But at least it could give you an idea!


greetings,
Johan

-- 
Johan Heuseveldt <johan@...              >
  aka  waarland

  The best place is a Riscy place
 
She sells seashells by the seashore