Date: Sun, 7 Dec 1997 22:51:45 -0500 (EST)
From: Paul W Brannan <pbranna AT CLEMSON DOT EDU>
cc: OpenDOS AT delorie DOT com
Subject: Re: memmax question
In-Reply-To: <199712080219.UAA05155@endeavor.flash.net>
Message-ID: <Pine.OSF.3.96.971207224530.6725A-100000@hubcap.clemson.edu>
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>     When checking memax at the prompt I recieve the following results:
> 
>      upper memory is enabled
>      no lower memory availble or dos not loaded high
>      memory is maped into viedo space
> 
>     I show lower, conventional memory available so I don't understand this
> message from memmax?

A common misconception is that lower memory and conventional memory are
the same thing.  This is not the case.

When DOS first came out, computers generally did not have 640k of memory,
and didn't really need it.  However, as things progressed, programs
started to use more memory, and there was a need to load DOS into high
memory.

When this happened, this broke some programs.  This was because those
programs did not expect to see more than 512k of memory available.  When
they did a signed comparison of how much memory was available and how much
memory the program required, the program thought there was a negative
amount of memory available and promptly exited.

To fix this problem, software engineers at Digital Research came up with
memmax.  Typing memmax -l would disable lower memory (the bottom 64k of
memory).  This way there would not be a problem with having too much
memory.  Lower memory can be enabled again with memmax +l.

I doubt you are disabling lower memory on accident, so the other
possibility is that you are not loading DOS high.  You probably just need
to add the line DOS=HIGH to your CONFIG.SYS file.

Paul