Econet

[Networking]

Econet

Introduction

Acorn's 1980 specification for Econet was:

Up to 255 stations per Econet

Econets may be joined together by Gateways

Connection by 4-wire cable to each station (typical cost in 1980 12p per metre)

Station seperation up to 1 Kilometre

Data transfer rate up to 210 kilobaud

Differential signals for high noise-immunity and minimal radiation

Crash-detect circuitry and colision-arbitration algorithm minimise the need for retries

Econet hardwarer fits inside Atom case; eurocard version for Acorn System 2/3/4

Econet software in 4K ROM, fits on Atom board

Econet executed automatically on BRK

The Econet network is totally democratic in that all stations have equal status and, unless specifically prohibited, any station may communicate with any other with recourse to an intermediary. The only unique station is the one that generates the network clock, but this may be an Atom or a larger system. On larger networks, the stations at the extreme ends are terminated, the termination circuitry is on the Econet board.

Here is a 1982 Econet network:

A shared disk facility is provided by a station dedicated to running a program known as the 'file server' which organises disc files for the network. The file station may be an Acorn system 3, 4 or 5 or an Atom with a disc. In the simplest possible configuration the printer station can be a printer connected to an Atom running the 'print server' program. In larger configurations the printer server will include a disc unit to spool files before printing.

Here is a 1984 Econet network:

The Econet architecture evolved and in 1981, Econet had seperated the terminators and clock from the Interface cards and made them dedicated devices. Meanwhile the stations had become BBC micros with Econet interfaces, although the File server was still a System 3,4 or 5.

Here is a 1988 Econet network:

A simple, "single-room" Econet network from 1988, where station 7 is a Filestore.

A complex Econet network from 1988, it links multiple buildings and uses bridges between them.

Documents

Here are some Acorn Econet brochures:

Here is the 1986 Acorn brochure APP81 Local Area Networking Econet .

Here is the Econet System user guide which documents the 1982 Econet system.

Here is the Econet Installation Guide which documents the 1984 Econet System.

Here is the Econet Installation Guide from 1988. The last 2 network diagrams, above, are in this manual.

Here are some additional Acorn Econet Manuals:

Econet Infrastructure

The Econet infrastructure is made up of:

Bridges, a bridge connects one Econet network to another network.

Clock boxes, an Econet clock sets the timing for the network and synchonises the fileserver and station Econet interfaces.

Terminators, terminators mark either end of an Econet network and stop the signals reflecting back down the network disrupting communication.

Socket boxes, socket boxes connect a station to the network via a flylead.

Cables and T-pieces, a T-piece is an alternative to a socket box for small networks. Cable link the Socket boxes (or T-Pieces together forming the network and flyleads connect stations to the socket boxes or T-pieces.

Stations, stations are computers with Econet interfaces which are connected to the network by a socket box or T-piece.

Econet servers, are computers running server software which provide file and print services to Econet stations.

Gateways, connect Econet networsk to other types of network.

Transient Supressors , to protect an Econet network from external electrical activity.

Acorn produced starter packs which contained all you needed to set up a small network. It the late 1980's it was the AEH19 Econet Starter Kit and in the early 1990's it was replaced with the AEH51 Econet Starter Pack . I have an example from the early 1990s, when the supply of Econet components has been outsourced to SJ Research.

Acorn produced Econet Test Boxes to test Econet interfaces.

Bridges

I know of 2 different Econet Bridges:

Acorn AEH20 Econet Bridge

SJ Research Econet Bridge [Wanted]

Clock boxes

I know of 4 different Econet Clock Boxes, 3 from Acorn and 1 from SJ Research. A number of Acorn Econet products can also include Econet Clocks e.g. System 3, 4, or 5 Econet interfaces, Atom Econet Interface, Econet bridge, Econet Filestore E01 & E01S. Also the SJ Research MDFS and BEN contain clocks. See the individual products for details.

Acorn Type 1 Clock is the earliest Econet clock

Acorn American Clock [Wanted]

Acorn Type 2 Clock

SJ Research Clock is reputedly the best Econet clock because of its flexibility in setting the mark and space timing and hence network speed

Terminators

Acorn Type 1 Terminator, The Type 1 Terminator is the same hardware generation as the Type 1 Clock,

SJ Research Terminator.

SJ Research Secure Terminator box, The Secure Terminator box has an internal 5pin DIN socket, which provides a neat thief-proof socket for SJ Research terminators.

Socket boxes

Socket boxes connect a station to the network via a flylead. There are both Acorn and SJ Research socket boxes.

Acorn Socket Box , the Acorn socket box connects 2 stations or a clock to an Econet network.

SJ Research Socket Box , connects 2 computers to the network,

SJ Research Split Socket Socket Box , is used to isolate the network into segments and typically to connect a clock or bridge to the network.

Cables & T-Pieces

Econet Cables and T-pieces , Cables and T pieces connect stations together. T-pieces are an alternative to socket boxes for small networks

Stations

Stations are computers with Econet interfaces connected to the network. With the BBC Master, Acorn designed an Econet module which was easy to install because it plugged into sockets on the motherboard. Acorn kept this design for all their subsequent computers up to the RiscPC, except for the A4 laptop. The RiscPC (and A7000) Econet interface plugged into the RiscPC network slot. Probably the only common Acorn computers which do not have an Econet interface are the Electron and the A3010, which were designed for home use.

All Acorn Econet interfaces use the Motorola MC68B54 advanced data link controller which controls the data transmissions.

Acorn System 3, 4 or 5 , the Acorn Econet Node interface is a standard Eurocard to fit into the card cage of a System computer.

, the Acorn Econet Node interface is a standard Eurocard to fit into the card cage of a System computer. Atom , I have heard of this interface, but I don't have one. [Wanted ]

I have heard of this interface, but I don't have one. [Wanted ] BBC Micro , the Acorn ANB22 Econet Upgrade added the Econet Interface and DFS ROM to a BBC Micro. Some models, including the US and German versions had it fitted as standard.

, the Acorn ANB22 Econet Upgrade added the Econet Interface and DFS ROM to a BBC Micro. Some models, including the US and German versions had it fitted as standard. BBC Master , the ADF10 Econet module was designed for the Master. This Econet module was also used in the Archimedes computers and A5000. There was also a special version, the Master ET , designed for use as an Econet terminal.

, the ADF10 Econet module was designed for the Master. This Econet module was also used in the Archimedes computers and A5000. There was also a special version, the Master ET , designed for use as an Econet terminal. A4 , the ALA66 Econet module was designed for the A4, because of the different design of the A4 and the need to fit into the selected case.

, the ALA66 Econet module was designed for the A4, because of the different design of the A4 and the need to fit into the selected case. A3020/A4000 , the AEH52 Econet module is an improved version of the ADF10 Econet module.

, the AEH52 Econet module is an improved version of the ADF10 Econet module. RiscPC, was designed with a seperate network slot and Acorn designed the AEH60 Econet card to fit it.

was designed with a seperate network slot and Acorn designed the AEH60 Econet card to fit it. IBM-compatible PC, in 1987 Acorn produced an Econet interface for a PC, this was the AEH30 Ecolink which was a full length ISA card. It was only supported under MSDOS 3.3, so is not much use in today's PCs. [Wanted ]

Third Party Interfaces

In addition to the Acorn Econet modules, at least 3 other companies produced Econet modules for Acorn computers:

HCCS, the HCCS Econet module is called a Network Board and was designed for Archimedes and A3000 computers.

the HCCS Econet module is called a Network Board and was designed for Archimedes and A3000 computers. Oak Solutions , the ClassROM/Econet card fits in the network slot of an A3020/A4000 and allows connection to an Econet network.

, the ClassROM/Econet card fits in the network slot of an A3020/A4000 and allows connection to an Econet network. White Wing Logic, the White Wing Logic interface is called Interclock and has space for the econet clock circuitry.

Econet servers

There are 2 types of Econet servers, file servers and print servers. File servers serve files to the stations on a Econet network and, except in very early Econets, a file server has one or more hard discs. An Econet network can have one or more file servers.



Print servers support shared printers, normally a print server is a BBC Model B with the AES22 Print Server EPROM and is dedicated to printing but can double as a Econet station.

Gateways

A Gateway connects an Econet network to another network.

Acorn AEH25 X25 Gateway, connects an Econet work to an X25 network (e.g. BT's PSS)

Transient suppressors

Transient suppressors block transient signals caused by external electrical events and protect the network. They are typically used where an Econet spans two different buildings to protect the network from external events (e.g. lightning strikes).

Test Equipment

Acorn also produced test equipment to help diagnose Econet faults.

Econet Software

While most Econet software was provided in ROM (on the client) or on the server by Acorn (or SJResearch), there were a number of thrird party Econet products. These include:

Angelsoft AppFS

AppFS is a software Application Accelerator which speeds the loading of software by client stations.



Here is Angelsoft AppFS Release 3 .

Digital Services Ltd NetGain

NetGain is a 'High Speed Application Loader'. NetGain was available for Econet or Ethernet and consisted of a Licence Card podule, end user licence packs and the software on a 3.5" disc. In use it marked reduced loading times. There is a review in Archive Vol.7 Isuue 1 (October 1993) page 77.



Here is the Digital Services NetGain Licence Card and more details of NetGain.