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Mail Archives: djgpp/1995/05/13/01:10:54

Date: Fri, 12 May 1995 23:44:18 -0400
From: dj (DJ Delorie)
To: jhunter AT kendaco DOT telebyte DOT com
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: Low memory access

>   I have seen DJ himself say that starting with version 2.0 you will no
> longer be able to use 0xE0000000 to access the first meg of memory.  Is this
> going to hold true for 0xD0000000 accessing video memory as well?  

Correct.

>   My guess is that it is, so we all will have to rewrite our video routines.
> Anyway, if we get the selector for linear memory from the go32_info_block
> structure at the very beginning of our program, are we assured that the
> selector will be valid (and won't change) for the duration of the entire
> program?  It would be a pain to keep accessing the go32_info_block everytime
> I wanted read from or write to video memory.

It will remain the same, but keep in mind that gcc optimizes accesses
to _go32_info_block to a single opcode, as fast as anything you might
do yourself.  What most people are complaining about is that typing
_go32_info_block.selector_for_linear_memory is too long.

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