How to use >640K memory on a 386 machine running dos 4.0?

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2 total messages Started by Baskaran Subramaniam Thu, 08 Mar 1990 03:46

#1496

Author: Baskaran Subramaniam
Date: Thu, 08 Mar 1990 03:46

9 lines
864 bytes

  A friend of mine in my department has a 386 machine running dos4.0.  He has
a Fortran program that supposedly needs more than 640K of memory to run.  He
has 4Meg on the machine.  Is there a way of using all this memory to run his
program?  BTW, what is the point of having 4Meg on a machine which runs under
an operating system that can address only 640K?  Could some kind soul 
enlighten me please.  

  Baskaran Subramaniam.

Re: How to use >640K memory on a 386 machine running dos 4.0?

#1520

Author: Stephen M. Dunn
Date: Fri, 09 Mar 1990 18:43

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In article <5826@udccvax1.acs.udel.EDU> bach@vax1.acs.udel.EDU (Baskaran Subramaniam) writes:
$ A friend of mine in my department has a 386 machine running dos4.0. He has
$a Fortran program that supposedly needs more than 640K of memory to run. He
$has 4Meg on the machine. Is there a way of using all this memory to run his
$program? BTW, what is the point of having 4Meg on a machine which runs under
$an operating system that can address only 640K? Could some kind soul
$enlighten me please.

It depends on what FORTRAN compiler your friend is using. If it's a
compiler for the 8086, then you won't be able to use that extra memory.
If it's one of the special compilers for the 80386, along with a DOS
extender, then the memory is accessible.

What's the point of having the extra memory? Well, if you insist on
running programs written for the 8086, then you can use the memory for a
disk cache or a ramdisk. Also, with the help of one of a number of
programs that use the 80386's memory management unit, you can use it as
expanded (LIM EMS) memory, and many programs (Symphony, WordPerfect, and
many others) will be able to use it (note that a program has to be
specifically written to use EMS if it's available ... you can't just take
any program and expect it to use EMS).
--
Stephen M. Dunn cs4g6ag@maccs.dcss.mcmaster.ca
<std_disclaimer.h> = "\nI'm only an undergraduate!!!\n";
****************************************************************************
"Oooh yes I need some love" - Rush

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