The PC is a standard hardware/software platform. PCs improve at a rapid pace, become cheaper,
and have more power than PLCs. Pentium® systems widely available today outperform even the fastest
PLC by margins of 20:1 or more [2]. A new generation of PCs becomes available every six to nine
months [1'21. By contrast new generation of PLC hardware becomes available every two to three years [:].
PCs with at least 16Mbytes are commonplace, while PLCs still have memory in the order of Kbytes. The
PC supports more standard peripherals/2] available from many vendors such as CD ROM drives, sound
cards, voice recognition, networking facilities, and so on, at very affordable prices. The PC is available
worldwide, on short notice, from many vendors