Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!uakari.primate.wisc.edu!ctrsol!cica!tut.cis.ohio-state.edu!att!cbnewsc!psfales
From: psfales@cbnewsc.ATT.COM (Peter Fales)
Newsgroups: comp.sys.ibm.pc
Subject: Re: HIMEM.SYS  loading device drivers past 1Meg.
Message-ID: <2158@cbnewsc.ATT.COM>
Date: 1 Aug 89 00:49:01 GMT
References: <26663@srcsip.UUCP>
Distribution: na
Organization: AT&T Bell Laboratories
Lines: 32

In article <26663@srcsip.UUCP>, rogers@orion.SRC.Honeywell.COM (Brynn Rogers) writes:
> 
>    I am under the impression that HIMEM.SYS can be loaded to use
> first 64K past 1Meg as real memory (on 286's only).
> 
>    How do I get it to work? I have a good 50K of device drivers that
> suck up my memory.  I have tried it (HIMEM.SYS) in the past but it didn't
> seem to make a difference, but before I go experimenting with it 
> again I would like to hear from someone who has it working right.


HIMEM.SYS does work, but only with applications and drivers that are
written to take advantage of it.  Microsoft has written a document on how to 
use it, and it is included on their "programmer's library" CD-ROM.  I
believe they may also distribute it for free to interested parties.
The purpose of this document is to come up with a standard method for
allocation of the memory above 1 Meg, both the 64K that HIMEM uses and
the remaining memory that RAMdisks, caches, etc. need to share.

The only thing I personally have used that knows how to take advantage
of HIMEM.SYS is Microsoft Windows/286, but it works fine there.  Windows
suddenly finds about 50-60K more memory when HIMEM.SYS is installed.

To repeat:  Normal DOS programs, TSRs, and even COMMAND.COM do not
normally take advantage of HIMEM.SYS.  (At least up to DOS 3.3)
If your applications don't use it, it probably even makes things worse.  I 
believe there is a small part of HIMEM.SYS that stays around in low memory.
-- 
Peter Fales			AT&T, Room 5B-420
				2000 N. Naperville Rd.
UUCP:	...att!peter.fales	Naperville, IL 60566
Domain: peter.fales@att.com	work:	(312) 979-8031