BeebMaster - I Want an Econet! - Build your own Econet

Build your own Econet

Positioning the Clock

Where the clock should go depends on what type of clock you are using. If you have a Level 1 or US-style clock (only one Econet socket) then the clock must be plugged into the network using a normal Econet lead at the socket or T-piece outlet nearest to the middle of the network. If you have an even number of sockets then it won't be exactly in the middle but near enough will do.

You are more likely to have an Acorn Level 2 clock or SJ Research clock. These each have two Econet sockets. You may connect the clock either in the middle of the network, in two adjacent sockets, or at one end of the network in the last socket. If you connect the clock at the end of the network, you will only need one lead. The spare socket must be filled with a terminator, either an SJ Research Terminator plug or an Acorn powered terminator box, and no other termination is required at that end of the network.

Positioning the Terminators

An Econet network should be fitted with terminators at each end of the network. Data may be reflected from the ends of the network because the net is a single line of cable and not circular. To absorb these reflections and prevent them corrupting data along the net, terminators are used.

Terminators may be either boxes produced by Acorn which look like socket boxes with only one Econet outlet, electrically powered boxes, or small silver plugs made by SJ Research.

An Acorn terminator box must be wired as the last box at the end of a network as if it were a socket box. An Acorn powered terminator is plugged into the last socket at each end of the network.

An SJ Research terminator is plugged into the last socket box socket or T-piece socket on the two-socket end of the T-piece. Alternatively, SJ Research terminators may be housed inside SJ Research Secure terminator boxes. These boxes are wired at the end of the network like an other socket box and the terminator plug is fitted inside. The idea behind this is to prevent access to the terminators thus preventing anyone removing them and disrupting the network.

If you have an Econet clock at one end of the network, then a terminator plug or Acorn powered terminator box must be fitted to the free socket on the clock box.

Although terminators are an essential part of Econet networks, it may be possible to run a small network without using them. If you really cannot get hold of any terminators then try running a net without them until you can get hold of a couple. I wouldn't recommend it as the network can be unreliable. In particular, BBC Master stations do not seem to like it as they tend to sit there for a long time just saying "Acorn MOS".

Attaching Stations to the Network

This is simply a case of taking an Econet lead from the Econet socket of the computer to a free Econet outlet along the network.

Broadly speaking, the Econet lead will be a 5-pin DIN to 5-pin DIN lead, wired straight through pin for pin.

Certain 32-bit Acorn machines, require specially made Econet leads as they do not have a DIN connection. The A3020, A4000, A7000 and RISC PC have a 15-pin D-type socket and the A4 has an adapted 6-pin mini-DIN socket.

There are instructions on how to make an A3020 type lead here and instructions on how to make an Acorn A4 Econet lead here.