27 Jan
2011
27 Jan
'11
5:55 p.m.
From: hilpert at cs.ubc.ca
Subject: Re: ENIAC ....
Date: Thu, 27 Jan 2011 15:54:57 -0800
To: cctalk at classiccmp.org
On 2011 Jan 26, at 4:14 PM, Evan Koblentz wrote:
Suppose we wish to solve the equation: z=xy+5
On a programmable analog computer, we program it by:
- plugging a cable from A to B
- plugging a cable from C to D
- setting switch K to 5
On the ENIAC, we program it by:
- plugging a cable from A to B
- plugging a cable from C to D
- setting switch K to 5
The difference is how the machine *executes* the program (.. just an
implementation detail).
So the analog computer solves it simultaneously rather than
sequentially - is it any less a program?
Would be interesting to look into when the word began being used with
computing machinery. Was it used for the differential analysers?, the
Analytical engine (in the period)?, what about early mechanical
automatons?
The Antikithera astronomical calculator 2K years ago, but there are probably calculating
and computing machines even before that.
A control system to regulate water for irrigation comes to mind, with a flow/level
measurement and balance to regulate water diversion into ditches. That probably goes back
500 - 1K years earlier.
What do you mean by 'calculating'? Does
this implky numerical
computions only?
My definition gets a tad awkward re: Colossus ...
How do you define the 'program' of an
analugue computer?
I was wondering the same thing. But I'm not losing sleep over it. :)