Date   : Fri, 16 Jan 2004 11:49:43 GMT
From   : Pete Turnbull <pete@...>
Subject: Re: unknown Acorn Econet board...

On Jan 14, 22:07, Jules Richardson wrote:
> Another oddity that turned up today:
>
> A long thin PCB labelled "Acorn Econet", part number 202,002 issue 2.
>
> There are 5 solder pads at one end, that would presumably link to an
> Econet connector.
>
> There's two ten-pin connectors at the other end of the board, which
must
> be for data and power.
>
> IC1 is just a 28 pin socket; I assume it should carry the standard
> Econet chip (the number of which eludes me right now, but I have
several
> spare)
>
> The board is about 12" long, 1.5" wide for about 8" of its length and
> then 2" wide for the remaining 4".
>
> I'm guessing it's for an Electron, having not seen the Econet board
for
> one of those; the size and shape I imagine are about right. Any other
> guesses though?

I don't remember an Acorn Econet board for an Electron, so I suspect
it's for an Atom.  HCCS considered an Econet in the same style for an
Electron, but I don't know if they ever built any.

Ah yes, it is for an Atom.  I've got the circuit diagram here.  It
shows a 20-way connector to the Atom.  Pinout (starting with Pin 1) is:

D6, D5, D4, /B400, D1, D2, D3, D0, /NMI (not connected), +5V, GND, A1,
D7, A0, A3 (not connected), A2, phi0, RnW, /IRQ, /RST.

The 5 solder pads go to the 5-pin DIN socket:

pad 1 - pin 3
pad 2 - pin 5
pad 3 - pin 2
pad 4 - pin 4
pad 5 - pin 1

That may look odd as text, but the layout will make sense when you look
at a DIN socket.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York