Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!altos!altos86!rcollins
From: rcollins@altos86.Altos.COM (Robert Collins)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: extended memory
Keywords: 286 extended memory
Message-ID: <4467@altos86.Altos.COM>
Date: 6 Dec 90 16:03:31 GMT
References: <18373@rasp.eng.cam.ac.uk>
Reply-To: rcollins@altos86.UUCP (Robert Collins)
Organization: Altos Computer Systems, San Jose, CA
Lines: 19

In article <18373@rasp.eng.cam.ac.uk> kap@eng.cam.ac.uk (Kevin A.Price) writes:
>We have a 286 PC/AT with 640k conventional memory and 384k
>extended memory which is located at address 1 Megabyte.
>
>we would like to do is to increase the amount of 'useable'
>DOS memory. Is it possible to load some of the TSRs and
>device drivers in the extended memory a la LastByte? We

Sure, there is.  Memory @ FFFF:0010 starts @ 1M.  To access this memory from
real mode, you need to enable A20 on the CPU address bus.  Then put your
TSR's @ FFFF:0010+.  Leave A20 always enabled.  If you run any benchmark
programs, or other software that uses extended memory, then this could
fail.  Also, you'll need to adjust a location in CMOS for the 'current' size
of extended memory.
-- 
"Worship the Lord your God, and serve him only."  Mat. 4:10
Robert Collins                 UUCP:  ...!sun!altos86!rcollins
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