Date   : Sun, 07 Aug 2005 12:51:15 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: Econet Bridge

On Sun, 2005-08-07 at 13:16 +0100, BeebMaster@... wrote:
> The Acorn Econet Bridge I bought from Chris Johns off E-Bay
> has arrived and it is slightly interesting inside because the top one
> of the 2 68B54 chips is in fact a 6854 which I understand is the 1MHz
> version as opposed to the 2MHz 68B54 version and the top one of
> the two 26LS30 chips is a 26LS34.
> 
> I wondered if the Bridge had been modified to run with a "slower"
> network, say a System or Atom network?

Hmm, that's interesing. Quite possibly so. Although I would have thought
the bridge just handles data at the rate which it sees it - so a bridge
made with faster parts would cope with fast or slow networks, but a
bridge built with slow parts might have trouble on a faster network.

Maybe reporting what IC dates are on the TTL chips would give an
indication of when it was built, if there's no other obvious date. Maybe
it's a very early bridge if nothing else. I'll have to have a look at
mine (picked up another one yesterday!)

There's a nice article in Acorn User issue 1 (IIRC) about Acorn
trialling Econet using an network of Atoms by the way (at my old
college, no less) - anyone able to put a scanned copy online?

> Or maybe it was just a question of replacing dud parts with what
> was available at the time.

Presumably the 6502 (and the board clock) are running at 1MHz too
though. Seems a strange thing to do...

cheers

Jules