Unless you are lucky enough to get your BBC with a factory fitted Econet kit, you may have to fit it yourself. This is not a trivial job as it requires a) sourcing suitable components and b) soldering them into the BBC motherboard.

What you will need

Integrated circuits


Capacitors


Resistors


Miscellaneous

Procedure

These instructions presume that you have first removed the full circuit board from the BBC model B case.

Solder all of the above passive components onto the main PCB.
Solder IC sockets into each IC position.
Insert all of the above ICs into their sockets.
Cut the wire links at link positions S2 (Econet NMI), S12 and S13 (S12 and S13 should already have been cut on the model B - they are ROM selects).
Set/ensure the following link positions using MOLEX jumpers:

S18 - North (IC100 fast access)
S19 - East (IC52/88/101 fast access)
S20 - North (high ROM select is ROMSEL1)
S21 - 2 x East/West (MOS is one ROM, not 4 EPROMs)
S22 - North (low ROM select is ROMSEL0)
S32 - West (A13 to pin 26 of ROMs IC52/IC88)
S33 - West (A13 to pin 26 of ROMs IC100/IC101)

On issue 1, 2 and 3 boards only the following additional modifications are required.
a) Remove capacitor C17 and replace with a 2.2nF capacitor.
b) Cut the PCB track from IC26 Pin 6 to IC96 pins 1 and 19 leaving the track from IC26 pin 6 to IC97 pin 2 intact.
c) Cut the track from IC89 pin 26 to IC97 pin 4 and link IC26 pin 9 to IC96 pins 1 and 19 and also to IC97 pin 4.

Econet Station Settings

Set the Econet station number by adding one or more link jumpers to the bank of links at
S11. Counting from North to South, the links are numbered 0 to 7, with each link
representing one bit in an 8-bit number. Installing a jumper sets the corresponding bit to
zero.

Seven jumpers are supplied so that the station number cannot accidentally be set to zero,
which is an invalid number. 255 is also an invalid number and should be avoided. 254 and
235 are usually reserved for file and printer server stations so should not be used unless the station being set is to have this function. 1 is the default number allocated to Econet
stations from the Master Series onwards and should again be avoided.

The table below shows the value assigned to each link when there is NO jumper present:

Link Value when NO jumper present
0 1
1 2
2 4
3 8
4 16
5 32
6 64
7 128

ANFS Option

The Advanced Network Filing System (ANFS) ROM (4.18) incorporates a number of improvements over the BBC B NFS ROM, including many more * commands in ROM and much faster BGET/BPUT routines to speed up loading of exec files, dumping of files etc.

In some cases, it will be necessary to install the DNFS ROM as well as the ANFS since the Tube host code and Disc filing system code are only contained in the DNFS. The ANFS ROM should be installed in a higher priority ROM socket than the DNFS to ensure it is recognised in preference to the standard NFS contained within DNFS.