I seriously doubt that base 10 was the problem. Victorian crypto people were already using base 24, 25 and base 26, base 60 arithmetic had been used for at least 3,000 years prior, and in any case, Victorian mathematicians were WAAAAY beyond bases. Dickson & many others were studying finite fields in the 1890's. I suspect that one could build a mechanical computer whose storage unit was a very large Oriental-style (i.e., base-10) abacus. My first IBM 1401 (~$250k) had 4,000 base-10 "characters" of memory; I believe it was possible to order 1401's with even smaller amounts of memory. I seem to recall that my first 1401 had a multiply instruction (my second one certainly did, and had 16,000 characters of memory), but multiply, too, was an extra cost option. A 4000 position mechanical abacus was well within the capabilities of Victorian technology; they had weaving looms which were nearly as complex. A machine shop circa 1900 was a huge array of spinning shafts & belts, because there were no small electric motors. Within 20 years most of those shafts & belts had given way to small electric motors. A moderately handy New England machine shop circa ~1900 could have built a 4000 position abacus, using such shafts & belts to control it. Heck, the Wright Brothers could have built such a device, had they not been sky-gazing! At 10:03 AM 4/2/2016, Tom Knight wrote:
Surely the major issue was the use of decimal rather than binary arithmetic. Decimal requires dramatically higher precision and complexity in the core units.
On Apr 2, 2016, at 12:50 PM, Mike Stay <metaweta@gmail.com> wrote:
On Sat, Apr 2, 2016 at 9:00 AM, Fred Lunnon <fred.lunnon@gmail.com> wrote:
As I understand it, Babbage's "analytical engine" failed because it pushed engineering techniques beyond their contemporary limits.
Even the difference engine pushed engineering past its limits; the analytical engine was never even attempted.
But in any case, I don't regard that as a "true" computer;
It would have been programmable, in much the same sense as an FPGA is.
The essential extra component is the "stored program", a development which had to await the concept of a universal Turing machine.
I think, had the analytical engine ever been built and employed, that the stored program would have followed shortly thereafter. -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com