Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!ncar!boulder!pikes!udenva!isis!csm9a!kamann
From: kamann@csm9a.UUCP (kamann)
Newsgroups: comp.sys.ti
Subject: Re: Addressable memory
Message-ID: <1664@csm9a.UUCP>
Date: 17 Jul 89 22:08:27 GMT
References: <4752@psuvax1.cs.psu.edu> <1643@csm9a.UUCP> <176@zip.eecs.umich.edu> <8958@chinet.chi.il.us>
Organization: Colorado School of Mines
Lines: 39

In article <8958@chinet.chi.il.us>, edlee@chinet.chi.il.us (Edward Lee) writes:
> In article <1657@csm9a.UUCP> kamann@csm9a.UUCP (kamann) writes:
> 
> >Now, I know that IBM is designed around the concept of a 64k paging
> >area (or the XTs were anyway).  So I think it would be safe to say
> >that an IBM only has 64k addressable also, or is it?!?
> 
> Intermediate conclusions based on incomplete evidence tend to be
> transitory.  It is safe to say that IBM PC-compatibles using the 8088
> or 8086-style of memory handling have a maximum LINEAR addressable memory
> of 64KB.  However, strictly speaking, IBM PC-compatibles generally have
> more than 64KB of addressable memory (note the absence of LINEAR).
> 
Then would it not also be safe to say that the TI "generally" has more than
32k of addressable memory?  Although the architecture is not there, something
along these lines could be developed from a software standpoint.  In addition,
the TI has 64k on it once the memory expansion is hooked up, and it is all
addressable, although not LINEAR.  I guess it comes down to a definition of
terms.
>
> Unix and Vax-like computers use page swapping because they have memory
> protection, i.e. some amount of protection from memory over-runs by
> different processes.  They may also be physically limited by the
> hardware architecture.
> 
To a point they are limited by the hardware.  Most machines of this size
have on the order of 4GB of memory, but will only address Megabytes for any
given process (and YES! That is virtual). Just for information, DEC VAX has
a 32-bit bus.

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 Keith Amann                       |    "WIZARD in training! GURU wanna be!" 
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 Disclaimer: The thoughts and views discussed above are my own, no one elses! 
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