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Mail Archives: djgpp/1992/05/22/12:37:45

Via: castle.edinburgh.ac.uk; Fri, 22 May 1992 17:00:26 +0100
From: htf AT ee DOT edinburgh DOT ac DOT uk
Date: Fri, 22 May 92 16:57:08 BST
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: physical addresses in gpp
Status: O

A previous enquiry resulted in:

>To: htf AT edinburgh DOT ee
>In-Reply-To: htf AT ee DOT edinburgh DOT ac DOT uk's message of Fri, 22 May 92 11:12:46 BST <2>13 DOT 9205221012 AT bogart-ee-net1 DOT ee DOT ed DOT ac DOT uk>
>Subject: physical addresses in gpp
>Status: RO
>
>Physical address = 0xe0000000 + segment*16 + offset.  Note that this
>only works when attempting to access the first 1 Mb of physical
>memory, as that is all I map there.  Read the documentation, this is
>described in there.

>DJ
>dj AT ctron DOT com
>Life is a banana.

Apologies for what was perhaps a misleading initial enquiry. Maybe
there is a quick answer to this which I have missed, I've only just
subscribed to the mail list.

I have a (frame grabber) board at address 0xa00000 which I need to read
and write to. This being outwith the first 1 Meg of physical memory
the above formula doesn't work. Is it possible to (easily) set pointers
to physical memory within source to be compiled by gpp? Alternatively
can the peek/poke memput/get functions in the extender be accessed
from within the program?

Thanks in advance
Hamish



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