>     1.  Generate a PWM signal.  If your PIC has a hardware PWM
>     generator, great... If not, do it in software.  Make the PWM
>     frequency as high as possible.

Apologies for what may appear a dumb question but with limited
electronics background I'm having a little difficulty in
understanding.

Is PWM just a method of sending out 5 volt pulses. The idea then is
to integrate (just did simple op-amp as an integrator in my
'Electronics for Beginners' night school) these to get some voltage
less than 5v. What considerations are there between pulse width and
space width?

Is there any good reference re PWM particularly relating to PICs and
especially for this sort of pot type application.
Brian Jones
Java Technology Centre
IBM Hursley