<From: Sam Ismail <dastar_at_wco.com>
<Now contrast this with an analog filter, which performs a singular
<function based on the laws of physics. No instructions, no codes, no
<processing unit. Therein lies the distinction.
The explanations of physics is based on the core of mathmatics.
That's one way to look at it. Consider it from the perspective of a
mathmatics view. Signal goes in FNC(x) is performed on it and signal
comes out. FNC(x) can be performed using a DSP or analog circuits
from the outside of the black box dos it make much difference how?
Computing is a process of calculation. Analogue functions perform
calculation vastly different than the digital forms it does not negate
the calculation performed. If this wasn't true digial signal processing
would not be possible.
I still have the Popular Electronics article that simulates the bounce of
a ball in analogue form using opamps while displaying it graphically on a
scope. Yes the ball would even flatten at the bottom of the bounce.
Years later I would write a program to do the same, the mathmatics were
unchanged as where the physics. The analogue form was faster at showing
how small changes had an effect, it could be real time. The digital form
allowed me to express those as floatingpoint numbers. Even on a PDP11 at
the time, it would never approach real time.
Allison
Received on Thu May 07 1998 - 21:20:17 BST