
2 Transducers
If a computer is to interact with the real world, it has to
be capable of exchanging data with it. This means that it
will be accepting some form of data input, processing it
in some way, then providing some form of output that is
related to this input. Some of the possible peripheral
devices that might be exchanging data with the compu-
ter were discussed in a general way in Chapter 1. In this
second chapter we shall consider some of the devices
that commonly provide data inputs. For the moment disk
drives will be excluded as they will be dealt with in more
detail later. Much of the present discussion will concern
a device know ...