Post by thread:Calculator chip ? [OT[

HP for instance uses special BCD chips and the math involved in functions like sin() takes several miliseconds to accomplish. They have ROM for constants like pi() and many other. I have an old HP jounal in which they state that and explain some algorithms. :-) J Souto Darren Logan wrote: {Quote hidden}> Hi, > > Anyone got any ideas as to which type of processors are used in calculators ? > > It makes me laugh because you can buy a calcultor with immense math power for > the price of a single PIC.. and yet a PIC is pretty poor in terms of it's > maths capability. Where's the logic in that ? (pardon the pun). > > Cheers, > Darren

Darren Logan wrote: > > > Hi, > > > > Anyone got any ideas as to which type of processors are used in calculators ? > > > > It makes me laugh because you can buy a calcultor with immense math power fo r > > the price of a single PIC.. and yet a PIC is pretty poor in terms of it's > > maths capability. Where's the logic in that ? (pardon the pun). > > > > Cheers, > > Darren Comparing a general controller to a specialized maths processor is comparing apples with bananas. Calculators are slow and used stored values for things like PI, but of course are very good at what they are designed to do. Comparing DSP chips with PIC's would make the PIC look fairly sick at FFT work etc. PICs (and the like) are low cost, fast controllers that run at low power levels and are easy to programme. P.S. There are serious safety issues concerning Hamburgers. 1. Hamburgers become unstable at high voltages 2. Hamburgers will not stop a high velocity bullet from 1000metres 3. Hamburgers will fail to restrain a crash victim at 120 km/hr 4. Hamburgers are inadequate as a ground proximity warning device in aircraft. 5. Hamburgers are known to have been eaten by %90 of fatal disease suffers. The list goes on....... _____________________________ Lance Allen Technical Officer Uni of Auckland Psych Dept New Zealand _____________________________

At 19:26 17/08/99 -0300, you wrote: >HP for instance uses special BCD chips and the math involved >in functions like sin() takes several miliseconds to accomplish. >They have ROM for constants like pi() and many other. I have >an old HP jounal in which they state that and explain some >algorithms. >:-) >J Souto > HP are changing tact on this one as the processors that they use are special one offs and are quite expensive to manufacture. They now are looking into actually using a real off the shelf processor! (Or one of several depending on the task and putting all the maths into software) Dennis >Darren Logan wrote: > >> Hi, >> >> Anyone got any ideas as to which type of processors are used in calculators ? >> >> It makes me laugh because you can buy a calcultor with immense math power for >> the price of a single PIC.. and yet a PIC is pretty poor in terms of it's >> maths capability. Where's the logic in that ? (pardon the pun). >> >> Cheers, >> Darren > >

I don't think that the chips are particularly powerful; Most of the TI graphing calculators, for example, use Z80 chips, although the high-end models (e.g. the TI-92) use MC68000s. Some functions are undoubtedly impemented as lookup tables, possibly with interpolation to fill out gaps in the tables. The apparant power that you see in those calculators is in part a reflection of how unbelievably powerful modern microprocessor chips are. Even a lame little go-ped of a chip like the Z80 can do basic floating-point arithmetic at what seems to a human operator -- who is concious only of wall clock time -- to be blazing speed. A PIC could probably be programmed to be a decent calculator, even handling double-precision floating point and 3D graphics, and at 20MHz would probably not seem all that bad. Even if it took 5000 clock cycles (at quarter the osc. frequency) to multiply two floating point numbers, you could still do such a calculation in a millisecond. The main problem one would have trying to do something like a TI-83 with a PIC would be memory capacity. PICs (at least mid-range PICs) don't have support for the of memory expansion that one gets with something like a Z80 or even an 8051. --Bob On Tue, Aug 17, 1999 at 06:01:29PM -0400, Darren Logan wrote: {Quote hidden}> Hi, > > Anyone got any ideas as to which type of processors are used in calculators ? > > It makes me laugh because you can buy a calcultor with immense math power for > the price of a single PIC.. and yet a PIC is pretty poor in terms of it's > maths capability. Where's the logic in that ? (pardon the pun). > > Cheers, > Darren -- ============================================================ Bob Drzyzgula It's not a problem spam_OUTbobTakeThisOuTdrzyzgula.org until something bad happens ============================================================

On Tue, 17 Aug 1999 18:01:29 EDT Darren Logan <.....DAZLOGANKILLspam@spam@AOL.COM> writes: >Hi, > >Anyone got any ideas as to which type of processors are used in >calculators ? > >It makes me laugh because you can buy a calcultor with immense math >power for >the price of a single PIC.. and yet a PIC is pretty poor in terms of >it's >maths capability. Where's the logic in that ? (pardon the pun). > Of course, the "immense math power" in the calculator is all in the software (or firmware), not in the chip. I imagine you could make a reasonable calculator with a PIC. Harold Harold Hallikainen haroldKILLspamhallikainen.com Hallikainen & Friends, Inc. See the FCC Rules at http://hallikainen.com/FccRules and comments filed in LPFM proceeding at http://hallikainen.com/lpfm ___________________________________________________________________ Get the Internet just the way you want it. Free software, free e-mail, and free Internet access for a month! Try Juno Web: dl.http://www.juno.com/dynoget/tagj.

I have a Texas Instruments TI-89 Graphing Calculator which has a Motorola 68k processor, however I don't think this is what you meant. The IC's in basic calculators would be custom made for that particular purpose and nothing else. On Tue, 17 Aug 1999, Darren Logan wrote: {Quote hidden}> Hi, > > Anyone got any ideas as to which type of processors are used in calculators ? > > It makes me laugh because you can buy a calcultor with immense math power for > the price of a single PIC.. and yet a PIC is pretty poor in terms of it's > maths capability. Where's the logic in that ? (pardon the pun). > > Cheers, > Darren >