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From: j@narcisa.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc,comp.unix.bsd.netbsd.misc
Subject: Re: Question on OS's
Date: 31 May 1995 12:45:44 +0200
Organization: Private U**x site, Dresden.
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[c.o.3.q is rmgroup'ed]
JARYX@DELPHI.COM <JARYX@news.delphi.com> wrote:
>
> I'm not quite sure if I should post this here, or where for
>that matter. In any case, here it goes. I am a newbie in the understanding
>of how an operating system is built. I don't seem to understand the
>difference between the XX-bit operating systems that exist. For instance,
>what is the difference between a 32-bit OS and its predecessor's?
>All help appreciated.
The main difference is the addressable address space. For a 32-bit
processor, it's 4 GB. For a 16-bit processor (or a 32-bit CPU in
16-bit mode, like MSDOG is working), it's only 64 KB. To work around
the 64 KB limit, the 8086 used a crock called "segmentation". Ask any
MSDOG programmer and he'll tell'ya that it's a pain in the ass to
program it.
For a 64-bit CPU, the addressable space is 2^64 = 1 TB.
--
cheers, J"org private: joerg_wunsch@uriah.heep.sax.de
http://www.sax.de/~joerg/
Never trust an operating system you don't have sources for. ;-)