Date   : Sat, 25 Jul 2009 00:42:27 +0100
From   : robert@... (Rob)
Subject: Econet Clocks and Modules

On 25/07/2009, Pete Turnbull <pete@...> wrote:
> A Master should, all other factors being equal, be able to very slightly
> outperform a B.  If it's very slow, it could be a faulty module, or one
> that is lacking the collision detect circuitry (which matters most if
> the rest of the net is below par).  The A5000 takes the same type of
> module as a Master.  If everything is OK, the A5000 should be capable of
> handling much higher clock speeds than the M128 or Beeb.  Maybe
> something is up with the clock or termination.  See below.  I've also
> seen this effect on a large network where some of the cabling was of
> poor quality (and had a lot of poor joints), but I'm guessing your
> network is not several hundred meters long :-)

lol no...  4 sockets at each end of about a meter of cable,  It's the
same 555-based clock and terminators I've had for 25 years.. but I
tried the acorn clocks i just got and they made things worse ...

Module wise, I've got two of Ian's modules, which were in the machines
when it all died, an acorn one that behaves just the same, an acorn
one that just gives me not listening errors, and one that's so badly
mashed up that I dare not try it...

Is it generally just the line driver IC that goes in these?  Or could
it be something else?


>
> Line Jammed is usually either a faulty unit on the net, holding the
> signal lines at an improper level, or is the result of a missing
> terminator.  However, it can also be caused by reflections if your
> network is T-shaped with a long extra arm (it should be linear, one line
> from end to end), but this is rare.

Hmm.. I just took the drop lead out of my clock, plugged it into the
acorn one... should have just worked.. sigh..

I'll have another play..