Acorn ADF10 Econet module Issue 1 (top)
Acorn ADF10 Econet module Issue 1 (bottom)
Acorn ADF10 Econet module Issue 2 (top)
Acorn ADF10 Econet module Issue 2 (bottom)
After the complicated upgrade to the motherboard for the BBC Micro, all Acorn computers until the RiscPC has an Econet port included and just required the Econet module installed. If you could open the case and get the pins on the bottom of the card (brown line in the picture) in the connector on the motherboard, you could install Econet!
The Issue 1 Econet module is the original Econet module produced for the BBC Master. Reportedly the issue 1 modules have collision detection disabled.
The Issue 2 Econet module restore collision detection but is otherwise identical to the Issue 1 board. The 2 holes in the card are for plastic supports which fit into the motherboard.
This Econet module was also used in the Archimedes computers and A5000.
Here are the Master Series Econet Fitting Instructions.