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Building a 5-Ton Calculator From 19th-Century Plans
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."
But does it run linux?
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Does this mean as a sysadmin that I should start wearing my Frock and Tophat and subscribe to the local Victorian club???? :)
How amazed would you be to suddenly find that you just forgot what I wrote and you needed to reread my post.... again.
Why you ask?
Because they can, and because they want to. Not everything required a practical use to be built.
But does it run linux?
We'll know about four years after it's completed - when it gets done with the boot-up.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
What happens when you divide by zero on a calculator using a physical engine?
Does it explode? Will it create a black hole? Could this be the next doomsday device?
When you can make an difference engine out of LEGO, it really doesn't seem that impressive to build a five ton one. Babbage's analytical engine, however... that would be an interesting piece.
File under 'M' for 'Manic ranting'
Here are some links :
http://www.fourmilab.ch/babbage/
The obligatory 99-bottles-of-beer-on-the-wall in punched card Analytical Engine assembly language :
http://99-bottles-of-beer.net/language-babbage's-analytical-machine-79.html
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
We do what we must
Because we can.
I don't know, but you can bet there will be "bad car analogies" analogies, mentions of some hot chick and grits, and complains about moderators.
What happens when you divide by zero on a calculator using a physical engine?
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.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
For example:
Windows XP
Vista
Science advances one funeral at a time- Max Planck
Here is the pic of the UK version.
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.
?
Hail Eris, full of mischief...
E pluribus sanguinem
Does it blend?
Karma is for whores
I guess that's why the author went into journalism instead of computers.
'The tyrant will always find pretext for his tyranny.' - Aesop's Fables
See what one (difference engine #2) looks like running, impressive!
This one is in mechano parts (Erector Set for us Americans)
http://www.meccano.us/difference_engines/rde_2/index.html
"Enjoy what you're doing! If it becomes drudgery, you're doing it wrong!" - Jim Butterfield
I'm am one of the Docents for the Difference Engine #2, and although the team making it work is WAAAAY more competent to comment, lemme put out a few FACTS, at the risk of "flame wars of death"... The Engine is a single function calculator that can iterate the values of a 7th order polynomial approximation to an arbitrary mathematical function. After about an hour of VERY careful setup, any set of coefficients could be entered, allowing almost any function to realized. It uses a technique called "finite differences" that allows the calculation to be performed using only addition (and 10's compliment coefficients to represent negative numbers). Our working plan is to set it up to do a table of logarithms, much like Babbage's own table, produced well before he thought of Difference Engine #2. The polynomial approximation for logarithms is quite accurate over the space from 1.0 to 1.6, 6000 iterations of the Engine. (It takes four turns of the crank or about 6 sec. per iteration.)
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
Almost any machine can run that one:
Stack overflow (core dumped)
[But does it run linux?] We'll know about four years after it's completed - when it gets done with the boot-up
If that's all you want out of the experience, run Vista.
Table-ized A.I.
4 years to get Ada working?
Domestic spying is now "Benign Information Gathering"
All those moments will be lost in time, like tears in rain. Time to die.
I remember reading that one of them was a congressman. If so, things haven't changed in 150 years.
Table-ized A.I.
It is possible using these materials and a potentially limitless but deterministic input source to make a universal Turing machine, but this device as designed and as it is not fully programmable (it was Ada Lovelace who pointed that fact out, along with a very early formation of the Church-Turing thesis when she commented in the margin that a suitably-designed engine could be alternately arithmetical or analytical depending on how the inputs and outputs were interpreted).
All's true that is mistrusted
But will it blend?
Sorry, I couldn't resist (8 ton blender? Beowolf Total Blender cluster?)
Same thing they're doing right now, I expect: Decomposing.
Breakfast served all day!
And that's just getting the livecd up. We've still gotta compile everything - "Deep thought" was just throwing an error from make.
www.isoHunt.com
Comment removed based on user account deletion
Simple: it's circular.
Shop as usual. And avoid panic buying.
The Difference Engine is a specialized device which was designed to automate the calculation of tables of values of complex formulae. Such as trigonometric functions, logarithms, etc. The Difference Engine works by using a variant of the Taylor method to approximate complex functions using high order polynomials. It then calculates successive values of the polynomial function using the difference method. It's quite elegant in terms of making the most out of limited computing ability.
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.
Pi are squared :)
Actually, it is at least possible that it was intended as a trick question. You know, one where if you say "yes" then you've just said "yep, I'm a con artist." Admittedly, it's a stupid one even as trick questions go, but still, there might be some purpose behind it.
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.)
A polar bear is a cartesian bear after a coordinate transform.
According to this article (which also contains more detail on building and shipping the Engine), the machine will be on display for 6 months, then it will be moved to Myhrvold's home. So if you want to see it, don't wait too long.
(I found another article 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.
You also forgot the "I for one welcome etc.." quote. But then again, in this case, its brain would be so slow, we would all have died of old age, long before it would finally be able to think up its first great chess move, in how to take control of the Earth.
... well apart from it stopping due to rust or a spanner in the works etc..
Still, it would be EMP proof, so although its slow, its hard to stop with impressive high tech scifi looking energy weapons
There are 10 kinds of people in the world... those who understand binary and those who don't.