8-bitters and multi-whatever

[Tony Duell]

> > Econet was available on just about all the Acorn computers -- 'Systems'=
> ,
> > Atom, BBC micro, Electron (? the Advanced User Guide for the Electron
> > mentions it), ACW, Archimedes. I wouldn't be suprised if it wasn't
> > available on the RiscPC too. Presumably it was used, or Acorn wouldn't
> > have persisted with it.
> 
> It was an optional extra on the Archimedes range - the case cutouts
> were there but you needs a small additional circuit board that plugged
> onto the motherboard and carried the controller logic and ports.

It was optional (rather than standard) on almost all Acorn machines. The 
only one I know to have had it as standard was the ACW.

For the 'System' machines, the Econet interface was not suprisingly an 
Eurocard you put in a spare slot of the cardcage.

For the Atom, there was a long, thin PCB that plugged onto the solder 
side (top) of the main PCB. I can't rememebr if the header plug for this 
to fit onto was standard on all Atoms, or whehter you soldered it in when 
adding the Econet upgrate. Since the Atom expansin bus was the same as 
the System bus, you could also use the System Eurocard with the Atom (and 
I hace an Atom where this has been done)

Beebs (and B+'s?) had the main PCB laid out fo the econet circuitry, but 
no compoennts were fitted. The upgrade was a 'bag of bits' that you 
soldered to the main PCB. Some early 'issues' of the BBC mainboard could 
take the Econet clock generator circuit too.

The Master and Archimedes machines took a little plug-in PCB containing 
econet circuit. There were at least 2 versions of this one had hardware 
collision detection, the other didn't. The same module is used, IIRC, in 
the Filkestore systems.

-tony