Britain emerged from the Second World War as a world leader in telecommunications, electronics and computer technologies.
It looked as though the post-war era would be a brave new age of scientific progress and creature comforts. But the reality - austerity, rationing and economic crisis - proved a little different from the vision.
The vision of the 1950s was of an all-seeing, all-knowing computerised network that would provide intelligent telephone services.
By the late 1980s, this had largely been achieved - but not quite in the way the planners had originally foreseen.
What they hadn't taken into account was the falling cost, greater capability and ever reducing size of processors. By the late 1970s, the new microprocessors were small and cheap enough to be placed in every kind of device - the telephones, fax machines and answer phones that plugged into the network.
In other words, more and more intelligence was delivered by the device rather than by the network. But the network still had to provide a suitable platform to allow the device to work well.
