Message-ID: <33DBB874.57DF@polbox.com>
Date: Sun, 27 Jul 1997 23:07:00 +0200
From: Tomasz Chojnacki <tcho AT polbox DOT com>
Reply-To: tcho AT polbox DOT com
MIME-Version: 1.0
To: Nate Eldredge <eldredge AT ap DOT net>
CC: djgpp AT delorie DOT com
Subject: Re: Mem mapped device questions
References: <199707261600 DOT JAA29611 AT adit DOT ap DOT net>
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Nate Eldredge wrote:
 
> >You wrote:
> >I am working with the PC frame-grabber board under DJGPP v1
> >(gcc v2.6.3).
> 
> Off the subject: You really should upgrade. 2.01 is the current version and
> it's much better!

I think the access to memory mapped devices is more simple
in DJGPP v1. I can simply use 0xE0000000 linear address instead
of manipulating __dpmi_physical_address_mapping and other DPMI
functions. I understand that DJGPP v2 is DPMI only environment
and such mapping is not possible but I have question:
Is the access to memory mapped device limited only by that
hardware or by the compiler also - that is:

should the access to memory mapped device be faster/slower or
the same comparing DJGPP v1 and DJGPP v2.

Thank you !

----------------
Tomasz Chojnacki
tcho AT polbox DOT com
----------------

P.S.
I am sorry for my bad English