Later BBC Master
Econet Interface
Issue 2
The components are really packed onto the Master Econet Module! There are 21 resistors, 9 capacitors, 7 integrated circuits and two connectors, all squeezed onto a board measuring just over 3 inches by 2 inches.
The two holes allow plastic supports to be mounted on the BBC Master motherboard to fix the module in place, although the 23 pins in the two connectors provide adequate support, as long as you don't press on the top left-hand corner of the module!