The Design of Software (CLOSED)

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Design of machine before?

Does Blaise Pascal and Charles Babbage both suffer from mechanical stability during those times when they are developing their mechanical devices? I have reread the history of Babbage that it was in 1991 that his machine where built.
Tuesday, July 19, 2005
Sorry, I am not sure what your are saying. Please restate your question.
Wednesday, July 20, 2005
DJ, Babbage made a mechanical device that we would call a computer. He used base 10 in the gearing and other things. Because he used base 10, he needed greater precision in machining the gears than existed in his day and age.

I would not call his difficulty "stability" or lack of it, but rather precision, and the choice of base 10 (well, look at your fingers and count them, which makes base 10 a very obvious choice). In the 1960s, the Soviets proved that base e was the most efficient base for computation, and they wasted enormous resources making base 3 computers (3 being closer to 2.71828 than is 2).
Wednesday, July 20, 2005
It sounds like the original poster was asking if Pascal's calculating machine (the Pascaline) had the same sorts of problems with mechanical stability as Babbage's machines (the Difference and Analytical Engines).

From what I remember, and a quick Google search seems to confirm this, Pascal's machines were actually built and sold commercially, though not particularly successfully. Pascal's machine was an adding machine, in the truest sense of the word. You could enter two numbers, turn a crank, and they'd be added together.

The whole thing probably comprised a couple of dozen gears and wheels, total. I couldn't find any references to mechanical problems with the design. One source did say that "only Pascal could repair the machines", but it's not clear if that was because there wasn't any kind of service manual, or qualified mechanics were hard to find, or what.

Babbage's Analytical Engine on the other hand, was intended to automate repeated calculations, supporting the basic 4 arithmetic operations, taking instructions from punch cards, and having a 1000 number memory. It was to have been driven by a steam engine. This is orders of magnitude more complex than a simple adder, so it's perhaps not surprising that Babbage wasn't able to get it constructed - for one thing, it would have been really really expensive (like those electromechanical computers in the 1940's).
Mark Bessey Send private email
Wednesday, July 20, 2005
I have read, but don't have a link, that the design of Babbage's computers were entirely within the capability of machine tools of his day. What kept him back was scope creep and lack of funds.
Monday, August 08, 2005

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