On 2011 Jan 24, at 1:09 PM, Tony Duell wrote:
'computer' is pretty much anything that
computes. The Antikythera
mechanism is referred to as a computer.
Actually I've been arguing for years that he Ant. is not a computer.
I wasn't aware anyone conisdered it to be a computer. The earliest
known
mechncail calculating device, sure.
I'm not fully acquainted with the Antikythera device but, it was
composed of >30 gears, with some sort of differential mechanism in
there.
I am not very familiar with it either, I should probably find out more
about it...
It solves a couple of equations in parallel. I'm
not completely clear
on how complex those equations are, i.e. whether they are more than a
single simple relationship each, but it wasn't a simple device, it was
more than a rotary slide rule.
Sure. But to me that's stil a calculator. It's a special-purpose machine,
and I prefer to reserve the term 'computer' for more general devices. But
I understand that others use the term somewhat differnently
Actusally, like some others here, I find this 'Is it a computer or not'
argument somewhat pointless. There are things that everybody would class
as a computer (I don't think anyone here would claim the PDP8/e on my
desk was anyhting other than a computer). Other things that nobody would
claim to be a computer (the 746 telephone currently sitting next to it,
for example). Othre things thate may or may not be computers. How about
the HP9810 sitting alongside my desk? The makers called it a
'calcualtor', It its basic form it handles digits only. But it is
user-programmable, and can be expanded to have a simple form of character
I/O. Is that a computer? How abotu the servo system of an RK07 hard
drive. That's a dedicated analogue computer by some definitions.
When things are close to being computers, even if they are not computers
by some definitions -- things like the ABC, ENIAC, the Ant, mechnaism,
etc then I doubt anyone who has a serious interest in classic computing
could be uninterested in them. Comptuers or not, they are certainly
importat, interesting deviecs that are closely related to things that
everybody calls computers.
For the sake of discussion, here are some incremental definitions of
'computer' (not to say that these are the only possible definitions):
1 - something that performs a computation/calculation
2 - something that executes a program automatically (solves an
equation
where the equation is more than one simple arithmetic operation)
3 - something that is programmable (can solve a wide variety of
equations)
4 - a stored-program (/universal) machine
Waht do you call machins that contain a stored program, even a
use-alterable stored progrma with loops, conditionals and subroutines
(say) but which doesn't actually perform any numerical computations? I
have deisgned a few such things over there years -- special-purpose
programamble control systems that repond to inputs and generate outputs.
Computers? Sequencers? Programamble controllers? Whatever you call them
they must be related to at least part of a 'computer'
-tony