Early Master Series
This was the first plug-in Econet Module, introduced in 1986 for the BBC Master Series. It followed the lines of the prototype module except that the DIN socket was provided as standard in the Master and not on the board. In this respect, the Master Series Econet module is similar to the early System and Atom Econet cards in having a row of 5 pins providing a direct electrical connection to the DIN socket.
This is the early version which is branded "B ECONET", a reference not to the BBC Model B but perhaps to "Project B", the development name for the Master series.
The early module continues with the policy of not providing collision detect circuitry on this board and hence it is relatively sparsely populated. This led to problems and the later interface was soon introduced.