Antikythera: 2000 year old computer reconstructed

[Klay]

Cool stuff!

[100mpg]

Originally Posted by Xeraux

If it calculates something it is "computing" it, is it not?

yup.

[Putts]

Say, I'm curious, is a slide rule considered a computer?

[kwisn]

Originally Posted by Putts

Say, I'm curious, is a slide rule considered a computer?

Uh huh! You betcha.

[Klay]

Originally Posted by Putts

Say, I'm curious, is a slide rule considered a computer?

I was thinking about that, too. By the broad definition, yes, an analog computer. Actually we're getting to the point where we can call almost anything a computer. How about a pencil and paper?

[Putts]

Originally Posted by Klay

I was thinking about that, too. By the broad definition, yes, an analog computer. Actually we're getting to the point where we can call almost anything a computer. How about a pencil and paper?

Yeah, on a slide rule, the operator is doing as much of the computing as the ruler is, so why not pencil and paper?

Anybody have a line to draw here?

[Surfer]

Originally Posted by Putts

Yeah, on a slide rule, the operator is doing as much of the computing as the ruler is, so why not pencil and paper?

Anybody have a line to draw here?

I'd say the slide rule is a computer. The user of a slide rule merely sets the inputs and observes the output.

For pencil and paper, the person holding the pencil is the computer.

[Putts]

The Wiki entry for Computer is pretty good.

Basically it says that to be called a computer it has to execute it's calculations automatically, and must be programmable.

They specifically menton the gun fire control computers I talked about above and say it's not a computer because it's not really programmable.

I'll half buy the argument as it is very special purpose and you couldn't reprogram it to provide a calculation for how much concrete to pour or something.

It was programmable enough to provide accurate answers for different ammo, wind, gun barrel changes, etc. however. And you could replace gears and cams for completely different guns and such.

It did not have a sequence of instruction that it would step through though, which seems to be a key identifying characteristic.

The Wiki artical on Calculators includes a mention of the Antikythera. Here's that bit:

Originally Posted by Wiki on Calculator

analog computers were constructed in ancient and medieval times to perform astronomical calculations. These include the Antikythera mechanism and the astrolabe from ancient Greece (c. 150-100 BC), which are generally regarded as the first mechanical analog computers.^[5] Other early versions of mechanical devices used to perform some type of calculations include the planisphere and other mechanical computing devices invented by Abū Rayhān al-Bīrūnī (c. AD 1000); the equatorium and universal latitude-independent astrolabe by Abū Ishāq Ibrāhīm al-Zarqālī (c. AD 1015); the astronomical analog computers of other medieval Muslim astronomers and engineers; and the astronomical clock tower of Su Song (c. AD 1090) during the Song Dynasty. The "castle clock", an astronomical clock invented by Al-Jazari in 1206, is considered to be the earliest programmable analog computer.^[6]

[Klay]

South Pacific nav computer

[Klay]

Originally Posted by Putts

It was programmable enough to provide accurate answers for different ammo, wind, gun barrel changes, etc. however. And you could replace gears and cams for completely different guns and such.

I'd say those aren't programming changes, merely different inputs. But replacing gears and cams might represent a programming change.

[Putts]

Yeah, the Wiki on computers alludes to a 'modern' definition for computer programability which includes stepping through a series of instructions.

There's also a whole Wiki on analog computers which mentions the Antikythera in its first line:

The Antikythera mechanism is believed to be the earliest known mechanical analog computer.^[2] It was designed to calculate astronomical positions. It was discovered in 1901 in the Antikythera wreck off the Greek island of Antikythera, between Kythera and Crete, and has been dated to circa 100 BC. Devices of the level of complexity as the Antikythera mechanism would not reappear until a thousand years later.

But I don't think those Wiki dudes have near the deathgrip on definition you do.

[Surfer]

Originally Posted by Putts

The Wiki entry for Computer is pretty good.

Basically it says that to be called a computer it has to execute it's calculations automatically, and must be programmable.

They specifically menton the gun fire control computers I talked about above and say it's not a computer because it's not really programmable.

I'd call the wiki article bullshit on that regard alone.

Anyone ever add some additional instructions to their pentium? No, the assembly level instructions you tell it to execute are the same opcodes as everyone else. Only the order changes.

[Klay]

Originally Posted by Surfer

Only the order changes.

Exactly...and that to me is the difference between a calculator and a computer. By my definition.

[Putts]

Originally Posted by Klay

By my definition.

Which is?

[Klay]

Originally Posted by Putts

Which is?

A computer is programmable, a calculator not.