From: Damian Yerrick <Bullcr_pd_yerrick AT hotmail DOT comRemoveBullcr_p>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: twin complement ......
Organization: Pin Eight Software  http://pineight.8m.com/
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NNTP-Posting-Date: Fri, 18 Aug 2000 15:09:47 GMT
Distribution: world
Date: Fri, 18 Aug 2000 15:09:47 GMT
To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

On Fri, 18 Aug 2000 16:51:12 +0200, "Florent"
<florent AT oih DOT rwth-aachen DOT de> wrote:

>>You cause quite some confusion, here, by using the wrong term. The
>>thing you're talking about is usually called 'two's-complement'.  It's
>>the way negative numbers are represented in integers, on almost all
>>existing types of computers.
>
>Yes that's right and this is the name that I have learn in France, but I
>quite newbye in computering and the documents I got from the controller I
>have to control, use the term 'twin complement'. Is it something else or
>really the 'two's-complement' ?

The operation that takes 0x123 and returns 0xfffffedd is, indeed, the
two's complement, and is represented in C on binary computers by the
prefix operator - (a hyphen or minus sign).

0xfffffedd == -0x123

Whether the two's complement is actually what your device returns is a
good candidate for some printf() debugging.

-- 
Damian Yerrick
"I refuse to listen to those who refuse to listen to reason."
See the whole sig: http://www.rose-hulman.edu/~yerricde/sig.html

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