Date: 23 Dec 1993 14:41:40 U
From: "jbabcock" <jbabcock AT netrix DOT com>
Subject: hardcoded address access/go32
To: "djgpp list" <djgpp AT sun DOT soe DOT clarkson DOT edu>

I am in the process of porting a piece of existing code to run using the go32
utility.  This code requires access to shared memory in the upper memory area
(640kb - 1024kb) on a PC.  Perhaps I am not up to snuff on the current PC
technology for memory management, but the documentation provided with the go32
utility is not clear in the respect of access to specific memory locations.

Is the UMB accessed by using the flat mode addresses from 640k to 1024k or
should the 'arena' address space be used?

Does access to the UMB require a switch to real mode?

If the arena address space is used, can UMB addresses be accessed?

Response with a short example program would be helpful!  I couldn't see
anything helpful when looking at the video drivers.  Thanks in advance.

Jim Babcock
jbabcock AT netrix DOT com
phone: (703) 793-1020