Fibre optic data communication:

When in 1870 John Tyndall, an Irish physicist working in the USA, showed that light can be guided, he could not have foreseen that little over a century later an increasing proportion of the world’s communications would be carried by fibre optic cables. Now, fibre optics finds application not only in vast telecommunication systems all over the world, but also in the home (hi-fi system, cable television). The RS232 interface presented in this article enables a computer to be connected to a variety of peripheral equipment via fibre optic cables.