Sender:	root AT delorie DOT com
Message-ID:	<38A44B1E.F54DCFB0@inti.gov.ar>
Date:	Fri, 11 Feb 2000 14:47:10 -0300
From:	salvador <salvador AT inti DOT gov DOT ar>
Organization:	INTI
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To:	djgpp AT delorie DOT com
Subject:	Re: Uptime and entropy in DOS
References:	<lra6ascbh1fu2d4738d44h09kpooc8ecta AT 4ax DOT com> <38A420E4 DOT 27CA35B2 AT americasm01 DOT nt DOT com>
Reply-To:	djgpp AT delorie DOT com

"Campbell, Rolf [SKY:1U32:EXCH]" wrote:

> Damian Yerrick wrote:
>
> > Is it possible to get the uptime of a DOS system?  I need more entropy
> > than the 32 bits I get from time(NULL) to initialize a pseudorandom
> > number generator.  Is there a predictable way to get at least 64 bits
> > of entropy?
>
>     On Pentium's, there is a 64-bit cycle counter, but the upper bits
> will always be zero unless the machine's been running a few years...

:-)), true, the first 19 bits (aprox) will be 0 if the CPU runs only one day at
400MHz. So "at least 64" can't be from here, but perhaps a combination of both
things could work.

SET

--
Salvador Eduardo Tropea (SET). (Electronics Engineer)
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