Econet was Acorn’s low-cost local area network system, intended for use by schools and small businesses. Econet is rumored to be an abbreviation of Economy Network, but Acorn were always careful to stress the Greek root, oikos, meaning “house”
Econet was first introduced for use with the Acorn Atom and Acorn System 2/3/4 computers in 1981. It became popular as a networking system for the BBC Micro and Archimedes computers. The Econet system was eventually supported on all post-Atom Acorn machines except the Electron, the A3010 and the eventually-cancelled Phoebe 2100. The system was supported by Acorn MOS, RISC OS and RISC iX.
Passive Econet Terminator
If you want to make your own Econet socket boxes, I suggest you follow this excellent guide : Building my Acorn Econet socket boxes