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Author Topic: How do calculators work so quick!  (Read 15989 times)

Offline lightarrow

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How do calculators work so quick!
« Reply #25 on: 15/03/2009 14:19:52 »
*cube* root  :)   So you don't necessarily have to talk about imaginary numbers, unless you want all three solutions.
 

Offline DoctorBeaver

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How do calculators work so quick!
« Reply #26 on: 15/03/2009 21:27:59 »
 

Offline Chemistry4me

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How do calculators work so quick!
« Reply #27 on: 16/03/2009 04:30:25 »
 

Offline LeeE

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How do calculators work so quick!
« Reply #28 on: 16/03/2009 12:02:37 »
Isn't the proper answer to this question because calculators don't need to work to a regular clock frequency?  Actually, I'm not so sure if this is the case now-a-days; although early calculators didn't require clocks it may be that even simple calculators now use cpus.
 

Offline tangoblue

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How do calculators work so quick!
« Reply #29 on: 30/04/2009 12:19:12 »
its weird - you ask a question on this site and it seems to just turn into a big, mad and sometimes pointless conversation... not a bad thing though.
 

Offline techmatt

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How do calculators work so quick!
« Reply #30 on: 30/04/2009 19:31:31 »
its weird - you ask a question on this site and it seems to just turn into a big, mad and sometimes pointless conversation... not a bad thing though.
I would not be so sure it is simple.
Some calculators really just have a very weak CPU and a BIOS (Basic Input Output System) that can tell the CPU to add or subtract. All other calculations are just variants of adding and subtracting. The good calculators also have a small about of RAM in them to store information. In essence they are mini versions of of a very basic computer. The average calculator (not the kind we would use) is noting more than a few counters.

Just an FYI your good calculator has more computing power than all the components of the Apollo 11 put together.
 

Offline Ultima

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How do calculators work so quick!
« Reply #31 on: 18/05/2009 17:00:50 »
Calculators are fast because most of the time they are not calculating!  ::)

They use hard wired tables of precalculated values for lots of things, and then do computation on the intervals between these values. (Remember log tables and times tables  ;)) Also they are usually calculating to a much higher precision than your PC for mathematics, the digits you see on screen are usually not the complete accuracy that was used for calculating, hence most calculators have an "extended" mode that lets you see more digits or calculate with more.

Calculators get away with this kind of thing to be fast where desktop PCs can't. PCs are a general computer and have to deal with far far far more calculations happening of various kinds with multiple inputs and outputs. With a PC you can calculate the n'th root of tan(x) whilst browsing a Science Forum about why your PC is so much slower than a calculator!

Scientific and programmable calculators are faster than a PC mostly because they have extra hardware implementations for maths operations AND don't have anywhere near the software overheads of a PC, they usually have a single program operating system which straight away gives you massive performance.

If you wrote a calculator program for your PC that was the only thing running from boot (no Windows) it would be incredibly fast compared to your hand calculator.
 

Offline LeeE

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How do calculators work so quick!
« Reply #32 on: 18/05/2009 17:34:17 »
Actually, the use of pre-calculated look-up tables is quite common in (PC) software too, especially in gaming software, although the look-up tables are calculated at start-up, rather than being hard-coded.  Trig tables, for example, are ideal candidates for pre-calculated look-up tables.

This is just one of the reasons that an executable that may only be a few MB in size can occupy considerably more ram when it's loaded (and before any data is loaded).
 

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How do calculators work so quick!
« Reply #32 on: 18/05/2009 17:34:17 »

 

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