>
> ----- Original Message -----
> From: "Mark Green" <mark_at_cs.ualberta.ca>
> To: <classiccmp_at_classiccmp.org>
> Sent: Tuesday, November 07, 2000 2:20 PM
> Subject: Re: "Basics of Analog Computers" book
> >
> > The last time I looked tubes were analogue devices. One of their
> > main uses is as amplifiers, which is definitely an analogue function.
> > If I remember correctly, one of the main problems with early tube
> > computers (1940s and 1950s), was actually getting the tubes to behave
> > like digital devices.
> >
>
> Point taken on the nature of tubes, but they were primarily used in
> computers as bipolar devices, weren't they? The fact that a computer
> contains analogue devices doesn't make it an analogue computer.
>
Depends. In the 1940s and 1950s they were used in both analogue
and digital computers. After the early 1960s, tubes were replaced
by transistors in digital computers (at least in North America), but
they were still used in analogue computers. In terms of pure numbers,
analogue computers greatly out numbered digital computers until some
point in the 1960s. In the simulation area, digital computers didn't
become cost effective for many applications until around 1970, particularly
those requiring real-time. So, for early computers the use of tubes
wasn't a good indication of whether the computer was analogue or
digital.
--
Dr. Mark Green mark_at_cs.ualberta.ca
McCalla Professor (780) 492-4584
Department of Computing Science (780) 492-1071 (FAX)
University of Alberta, Edmonton, Alberta, T6G 2H1, Canada
Received on Tue Nov 07 2000 - 16:32:37 GMT