Date   : Wed, 29 Aug 2007 12:58:53 +0100
From   : robert@... (Rob)
Subject: Econet oddities

On 29/08/2007, Chris Priest <chris.priest@...> wrote:

> I'll check that, I have 4 socket boxes each connected with approx 1m of
> cable between each box, the cable is screened 4 core from maplin, I have
> some twisted pair, maybe I should give that a go.  a point to note, the
> boxes are SJ research ones and the krone blade terminals were a tad
> knackered (another source of problems!)  so I soldered the cables
> directly to the circuit board, I have done a test, each pin is wired
> correctly and there are no shorts.

It sounds like you've done your best, but it is almost certainly the
wrong cable; econet uses a differential signal like ethernet 10baseT
rather than a signal-to-ground like RS232/432 seral.  For this to work
reliably at speed, the cables in the pair are supposed to be twisted
together, and always kept the same length.

Also, whats in the cables from your sockets to the Beebs?


> The cable is shielded, the shield being used as earth.

Make sure you only connect shields at *one* end to avoid creating hum
loops ...

>
> have tried to slow the clock, but it doesn't appear to solve the
> problem, might see if I can obtain another clock or possibly spring for
> one of Ian's clocks :)
>

I think mine is a homemade one (not by me) using a 555 ... I really
need to trace it out sometime & post a schematic..

Rob