Re: [CAD_CAM_EDM_DRO] Re: Conversion

On Fri, 21 Jun 2002 23:53:58 -0000, you wrote:

>Hi,
>
>I think the calculator in Windows "Programs / Accesories" must do the
>math in software instead of using hardware. Fixed point decimal math
>is carried out to 32 digit precision, hex math is fixed point, 64 bit
>precision. Pi is correct to 32 decimal places as well. I have tested
>a few transcendental functions for accuracy and it seems to be there
>to 32 decimal places.

Nope - done by the chip, remember all the hooha about the "Pentium
Bug" circa November 1997.

Here's an interesting one I found this morning..

"Floating-point numbers are stored inside the microprocessor as
strings of 80 bits, whereas integers are stored in 16 or 32 bits.
Sometimes a floating-point number converted to an integer doesn't fit
the smaller format, and the microprocessor is supposed to provide an
"overflow" warning. The Pentium II didn't.

Interestingly, the launch failure of the Ariane 5 rocket, which
exploded 37 seconds after liftoff on June 4, 1996, occurred because of
a software error that resulted from converting a 64-bit floating point
number to a 16-bit integer. The value of the floating point number
happened to be larger than could be represented by a 16-bit integer.
The overflow wasn't handled properly, and in response, the computer
cleared its memory. The memory dump was interpreted by the rocket as
instructions to its rocket nozzles, and an explosion resulted."

>Besides Intel would never make a mistake like that; I am using the
>very latest Pentium 3.999999999999965319 CPU.

<G>

The people who crashed that Mars probe probably used a similar
conversion factor ;)


Steve Blackmore
--
Pilot Consultancy Limited ***** Computer Consultants
Telephone 01744 752256 Mobile 07831 768478
Email: steve@... WWW: http://www.pilotltd.net