From:	"Florent" <florent AT oih DOT rwth-aachen DOT de>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: twin complement ......
Date:	Fri, 18 Aug 2000 11:07:58 +0200
Organization:	Aachen University of Technology (RWTH)
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To:	djgpp AT delorie DOT com
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>1) This function will work quit slow (if you're going to use it in some
loop
>for example)

ah, why ? because of all tests ?
no it's not in a loop, I use it three times when I receive some special
datas from the machine.

>2) Can you tell me what exacly is twin complement ? How this function is
>suppose to work ?


a twin complement is :
int x=0x10
in bin x= 0001 0000
wiht the first complement we get 1110 1111 (replace all 1 by 0 et 0 by1)
the n with the 2nd complement we had 1
1110 1111
+               1
_________

1111 0000

so the twin complement of 0x10 is 0xf0
usually it's used for the negative number, but here I received some datas
from a machine and I need to do the twin complement to read the value.

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