Building a 5-Ton Calculator From 19th-Century Plans 218
alphadogg writes "Starting in May, many will have the opportunity to see computing done the old-fashioned way: with lots of gears, a big crank, and some muscle. The Computer History Museum in Mountain View, CA, will unveil a new construction, the first in the US, of the 19th-century British mathematician Charles Babbage's Difference Engine No. 2, an improved version of his earlier design for a mechanical digital calculator. It weighs in at two tons more than the Difference Engine built in 1991 at London's Science Museum. Microsoft millionaire Nathan Myhrvold commissioned and paid for the US model."
It's cool (Score:4, Funny)
Re:It's cool (Score:5, Insightful)
yep.
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its weight is about 1.002 African Elephants.
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I don't know what I'm doing wrong, but it always gives me 42.
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You also forgot ... (Score:3, Insightful)
Still, it would be EMP proof, so although its slow, its hard to stop with impressive high tech scifi looking energy weapons
We'll know about four years after it's completed (Score:5, Funny)
We'll know about four years after it's completed - when it gets done with the boot-up.
Re:We'll know about four years after it's complete (Score:4, Informative)
If that's all you want out of the experience, run Vista.
Re:We'll know about four years after it's complete (Score:4, Informative)
gentoo (Score:5, Funny)
Re:It's cool (Score:4, Funny)
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Re:It's cool (Score:4, Funny)
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Re:It's cool (Score:5, Funny)
Yes, but first you have to figure out how to approximate Linux as a Taylor series.
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http://en.wikipedia.org/wiki/Babbage#Analytical_engine [wikipedia.org]
As a practical matter you may want to invent a time machine and perpetual power source first.
Re:It's cool (Score:5, Insightful)
First, this is the Difference Engine No. 2, not the Analytical Engine. It's not Turing complete.
Second, the usual restriction on running something like Linux is lack of memory, not lack of a Turing-complete instruction set. Or, looked at another way, no one has ever or will ever build a Turing-complete machine, because they'll run into difficulty with the infinite tape.
Negative. This is a DFSM (Score:4, Insightful)
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Now for a number that'd be really hard to believe, think about the cache latencies waiting for the assistant to put in the next card.
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I heard they are porting Gentoo to the Babage platform (think its called Garbage), should be finished compiling the kernel in about 15 years.
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The more important question (Score:3, Funny)
But will it blend?
Sorry, I couldn't resist (8 ton blender? Beowolf Total Blender cluster?)
frock (Score:5, Funny)
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Hold on. (Score:2)
...an improved version of his earlier design for a mechanical digital calculator. It weighs in at two tons more than the Difference Engine built in 1991 at London's Science Museum.
Well - there goes Moore's Law then, I guess. Although, this was invented in the century before Moore himself was.
Microsoft millionaire Nathan Myhrvold commissioned and paid for the US model."
Hmm. Microsoft's upcoming answer to viruses, rootkits, worms, etc?
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Well - there goes Moore's Law then, I guess. Although, this was invented in the century before Moore himself was.
Improved model? (Score:5, Funny)
Re:Improved model? (Score:5, Funny)
You can't necessarily go by version (Score:3, Funny)
Windows XP
Vista
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Windows 98
Windows ME
(Actually, Vista doesn't piss me off like XP always did. It's still Windows, but Vista's compatibility problems aren't any worse than XP's were six years ago. And I leave UAC turned on, because even though it's a piece of crap, it doesn't get in my way unless I'm trying to do things I don't frequently do. But even Microsoft wishes Windows ME never existed.)
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What if... (Score:5, Funny)
Does it explode? Will it create a black hole? Could this be the next doomsday device?
Re:What if... (Score:5, Funny)
Re:What if... (Score:5, Funny)
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The theory also mentioned that this has happened a few times already...
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Re:What if... (Score:5, Funny)
(maybe v2.1 now - there was a service pack applied a couple of thousand years ago according to some reports)
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Re:What if... (Score:5, Informative)
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EG National cash registers and even the solenoid powered electric adding machines with paper tape printing.
It's only microprocessors that can't handle div by 0 errors.
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Re:What if... (Score:5, Informative)
I've done that. (Score:5, Interesting)
I've done that.
The particular calculator in question would spin madly, with the result digit dials working like a cross between an odometer and a clock movement, until you hit the button that aborts the process. (The abort apparently consisted of changing the divisor to a large number. It took close to a minute as the machine would do a trial subtraction, undo it, shift the register bar one to the left, and repeat until it got to the last digit.)
Re:What if... (Score:5, Interesting)
"On two occasions I have been asked, "Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question."
What truly happens to an impossible sum?
Does it dry up
like a slashdotter in the sun?
or does it fester like sco
and then run?
does it stink like an overused meme?
or crust and sugar o'er--
like a deferred dream?
maybe it just sags like a 5-ton calculating machine under a heavy load
or does it explode?
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GIGO (Score:3, Funny)
I remember reading that one of them was a congressman. If so, things haven't changed in 150 years.
Sounds like a trick question (Score:5, Interesting)
To put things into perspective Babbage got funding for one machine, never finished it, decided he's rather begin designing the version 2 model, asked for more funding, repeat ad nauseam. Pretty much it was _the_ original computing vapourware. Pretty soon he got no more funding, but that never stopped him from asking for more and hyping his unproven creation to the parliament.
He also seems to have descended into a nerd-like bitterness, in which he took such questions out of context as proof that everyone else is a drooling idiot and that's why they don't see he's right. And in that he also included such questions as, basically, "well, what _can_ it do?" and "what's the business advantage for making one of these?" Stuff that you'd get asked by any business nowadays too. He took them as proof that his contemporary Englishmen were narrow minded and lacking in vision.
It may seem obvious in retrospect that his design was right, but at the time it was everything except obvious. It was a _monumental_ expense with the economy and technology at that time, even compared to paying armies of people to calculate those by hand. And it was anything but proven. Noone knew if it would even work at all. Again, the first round of funding he got, produced nothing tangible.
Also regarding the parliament at the time, they were not as obtuse as you (or Babbage) seem to think. They funded a lot of research, actually. The nautical clock, for example, was paid for by the parliament, and that was quite the iterative development. The first couple of versions not only were too inexact to be any use, but at least the first one didn't even compensate for the ship's rolling around. But nevertheless, that guy had _something_ working to show for his work, and kept getting more money to keep working. Babbage had nothing except his claims.
Now before I sound too damning to Babbage, it wasn't only his fault. He got into a conflict with the company actually building it, and that was the chief reason why the V1 was never completed. But, still, seen from outside, he never had anything working to show, and even more damning he just unilaterally scrapped the design in the middle of the project and began designing an even more overengineered V2 instead.
So, anyway, given that he was technically hyping vapourware, I can see a smart-arse member of the parliament trying to catch him with a trick question. Again, it _is_ a dumb one, but it's not the same class of dumb as actually thinking that a machine can magically guess the right answers when fed wrong data.
(But then again, I see a ton of PHBs and businesses nowadays believing just that about electronic computers, so maybe it was just a dumb question after all.)
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Pun Engine (Score:2)
"Careful, Babbage, you could put out somebody's pi with that thing."
I thought Microsoft already built this... (Score:2)
(Yes, even Microsoft users can poke fun at themselves too...)
Meh.... (Score:5, Interesting)
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It appears Mr. Babbage should have invented Legos first.
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Re:Meh.... (Score:4, Insightful)
Nor can you build a seventh order difference machine out of legos.
Only the difference engine? (Score:5, Interesting)
Here are some links :
[fourmilab.ch]http://www.fourmilab.ch/babbage/ [fourmilab.ch]
The obligatory 99-bottles-of-beer-on-the-wall in punched card Analytical Engine assembly language :
[99-bottles-of-beer.net]http://99-bottles-of-beer.net/language-babbage's-analytical-machine-79.html [99-bottles-of-beer.net]
Hmmm, I dare say that's shorter than the C# version, if you remove the comments. Oh and it will run Linux, if you have enough coal and are willing to wait a few years for X to load. ;) (it does have a graphical output device) As for a beowulf cluster, that might help performance, although your interconnect mechanism would probably be pneumatic ie. tubes (that's what the Internet is made of anyway right?) and the cluster size would require a few tens of millions of units. ;)
jdb2
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The problem is that there are no complete plans for an Analytical Engine. Drawings and diagrams, yes, but nothing complete. For Difference Engine No. 2, the Science Museum had a (reasonably) complete set of plans. (They had to make a few tweaks, but they did everything they could to keep it in the spirit of the original design.)
Doron Swade's book The Difference Engine: Charles Babbage and the quest to build the first computer is a marvelous read; it was published in the U.K. as The Cogwheel Brain. You may
"History,it seems,is not without a sense of irony" (Score:2)
Re:Only the difference engine? (Score:4, Funny)
Before we had the formal concept of "programs" (as defined and refined by Backus and Naur), computation machines calculated numbers based on information fed into them on paper tape. A full set of instructions on paper-tape was called a "tour", and while the program was running the computation machine was said to be "touring" or "turing" (Fr). When the end of the tape was reached, the computation machine was said to be in the "turing complete" state (i.e. the tour was complete).
The term "turing complete" came to mean any computer which could run any program fed into it to completion (assuming correct input, of course). We use the term "program" and "run" to talk about computer input nowadays, but we still use the term "turing complete" to describe our general purpose computation devices (computers).
Re:Only the difference engine? (Score:4, Informative)
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Re:Only the difference engine? (Score:4, Informative)
No. Turing Completeness describes a Universal Turing Machine that can emulate every possible computing device ever built. It was not named as such for "touring", but the Church-Turning thesis. As in Alan Turing.
Babbage's Analytical Engine design would have pretty much met the definition of a Turing Complete machine.
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Turing completeness makes no claims to represent "every possible computing device". I think some analog computers aren't, but I don't remember the details.
http://en.wikipedia.org/wiki/Turing_completeness [wikipedia.org]
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Don't know if this will be clearer, but... (Score:2, Interesting)
The Turing Machine is very simple, but given unbounded time and storage, it is believed to be able to calculate anything that can be described by a discrete set of steps (i.e. an algorithm).
Where this gets interesting for evaluating computer sy
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Stack overflow (core dumped)
Gear jam of death (Score:2)
Manager "What happened here I heard this unearthly explosion ? "
[a pallid skinned, slightly chubby man is sitting in the corner wearing shredded clothes and has black burn marks on his face]
BOFH "I tried to port Quake II to the Babage machine and I needed to over clock it a bit and well one of the gears on the number 5 stack jammed when it reached 24,000 rpm"
Picture it (Score:2, Interesting)
The login screen (Score:5, Funny)
WELCOME TO THE BABBAGE ANALYTICAL TIMESHARING SERVICE
PLEASE NOTE THAT THE INTEGRATOR IS CURRENTLY UNAVAILABLE
DUE TO THE WEEKLY GREASING SCHEDULE. WOULD ALL USERS KINDLY
RETURN ANY UNUSED PLUGBOARDS, AS THE PROGRAMMING TEAM ARE
RUNNING LOW. DIVISION UNIT 3 WILL BE OUT OF ACTION UNTIL
THURSDAY DUE TO EMERGENCY COG REPLACEMENT - PLEASE ENSURE
THAT YOUR PROGRAM DOES NOT ATTEMPT TO DIVIDE BY ZERO AS
THIS CAN CAUSE SEVERE DAMAGE (INCLUDING SHAFT BREAKAGES).
.
.
SYSTEM READY.
?
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Being British, I'd have liked a reference to the Memory Hole - I'm sure that Mintrue would have run some variant of the Analytical Engine...
I think I speak for everyone when I ask... (Score:2, Funny)
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My god why?! (Score:2)
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Guess that's why (Score:5, Funny)
I guess that's why the author went into journalism instead of computers.
An idle question... (Score:2)
I have visions of a multi-storied, block-sized, brass behemoth, with hundreds of workers scurrying around its innards "de-bugging" (and de-ratting) it, and keeping it lubricated.
Just interested to hear peoples guesses.
See it in action! (Score:5, Interesting)
This one is in mechano parts (Erector Set for us Americans)
http://www.meccano.us/difference_engines/rde_2/index.html [meccano.us]
Actual Information - GASP! (Score:5, Interesting)
The calculation section has about 4,000 parts, and a very elaborate printer mechanism has another 4,000, and was designed to produce sterotype molds of a complete page of a book of tables.
It is a WONDEROUS device to behold! There are 52 distinct stages in it's control graph (EXACTLY like a modern timing diagram, just vertical...) An elaborate nest of 14 cams control the complex sequence of events to do an iteration, which is !pipelined!. The sinuous ripple carry mechanisms on the back side are HYPNOTIC, as are the forward and backward movements of the intra-column sector gears.
Avoid CHM on May 10, it's gonna be a madhouse! But this is pretty close to the top of the list of "1000 Geeky Things to See Before You Die", oh, and by the way, there's all the other ABSOLUTELY WAY COOL stuff at CHM, wanna see an Apple I signed by "the Woz"...
YOU GOTTA SEE THIS! chmguy
How it works (it's not a general purpose computer) (Score:4, Informative)
Consider a simple polynomial like x^2 + 3*x. Now, take a few initial values of that function like so:
f(0) = 0
f(1) = 4
f(2) = 10
f(3) = 18
f(4) = 28
Now, take the difference between each value where x is increased by the same amount (equivalent to a crude approximation to the derivative of f):
g(1) = f(1)-f(0) = 4
g(2) = f(2)-f(1) = 6
g(3) = f(3)-f(2) = 8
g(4) = f(4)-f(3) = 10
Now do the same with these differences (equivalent to taking the 2nd derivative):
g(2) - g(1) = 2
g(3) - g(2) = 2
g(4) - g(3) = 2
Now we see that the 2nd differences are all the same value, this is because this is a 2nd order polynomial. For a cubic polynomial it takes 3 sets of differences. Now, we can calculate the value of f for x=5 and higher values without the formula by adding the differences.
g(5) = 2 + g(4) = 12
f(5) = f(4) + g(5) = 28 + 12 = 40
f(5) = 5^2 + 3*5 = 40
etc.
We can use exactly the same process to merely approximate functions based on a table of values, given we calculate the differences to a high enough order (i.e. produce a polynomial approximation of high enough order) to give reasonably accurate values. Meaning, taking differences as above to some nth degree from n initial input values and then calculating successive values has the effect of approximating that function with an nth degree polynomial.
Babbage's Difference Engine No. 2 design is capable of calculating 7th order polynomials with 31 decimal digit numbers, which is sufficient to calculate trigonometric and logarithmic functions to very high precision. Using the Difference Engine one would need to manually calculate only 7 initial values, then use the Engine to automatically produce tables for the remainder of the values needed. Compared to the methods of the 19th century (where the term "computer" referred to a person given that job, not a device) this represented an enormous savings of labor, as well as an enormous increase in accuracy of the output, under the right conditions.
It's a pocket calculator (Score:2)
Size and weight (Score:2)
What's the difference (Score:2)
See it while you can-limited time offer (Score:3, Informative)
(I found another article [wired.com] which claims the Engine will be at the museum for a year. The CHM website doesn't have definitive data.)
I saw the one at the Science Museum a few years ago, and it's awesome. Well worth a trip.
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Because they can, and because they want to. Not everything required a practical use to be built.
Because. (Score:2)
Seriously...thats all.
Re:Why? (Score:5, Funny)
Because we can.
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Somehow I don't expect this difference engine to start baking people cakes.
Aikon-
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Re:150 years makes quite a difference (Score:4, Funny)
Same thing they're doing right now, I expect: Decomposing.
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;P
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Re:I want to know... (Score:4, Funny)
Pi are squared :)