Path: utzoo!utgpu!watmath!att!dptg!rutgers!usc!cs.utexas.edu!uunet!cs.dal.ca!lane
From: lane@cs.dal.ca (John Wright/Dr. Pat Lane)
Newsgroups: comp.sys.ibm.pc
Subject: EMS support on a 386
Message-ID: <1989Aug31.111435.11940@cs.dal.ca>
Date: 31 Aug 89 11:14:35 GMT
Distribution: comp
Organization: Math, Stats & CS, Dalhousie University, Halifax, NS, Canada
Lines: 44

We have a 286 clone and a 386 clone, both based on Chips & Technologies
chip sets.  The 286 is a "Neat" motherboard while the 386 is a "Cache-32".
The both have AMI BIOS and 2 Meg of RAM.

The 286 has hardware EMS support on the motherboard (apparently part of 
the Chips & Technologies stuff) and a disk was supplied containing a 
software driver to allow DOS pgms to access the extra RAM as EMS.

The 386 has no such thing (or at least the doc. makes no mention of EMS).

I'm curious, first, as to why the 286 has the EMS hardware while the 386,
of similar design and vintage, is without.

Secondly, I wonder what the function of the software driver on the 286 is.
Does it merely tell the hardware that EMS is desired, how much EMS is
desired, what page segments to use, etc.  Or does it perform other
interfacing or translating fuctions.

Finally, what does one do to get EMS on a 386?  I gather there are software
drivers which emulate EMS using extended RAM.  I have Microsoft MSDOS 4.01
which has an EMM386.SYS.  Does this do the job?  I had heard somewhere that
this was brain damaged and only worked properly with True-Blue IBM machines.
Any truth to that?

What about HIMEM.SYS which apparently lets DOS use 64K of extended RAM.
Does it work at all in a 386 or 286 clone?  Is it safe?  What about in
combination with EMM386.SYS or other things that use extended memory?

I have noted a curious bug which seems to be associated with HIMEM.SYS.
DOS will get mixed up about directories, seeing one directory when it's
supposed to be reading at another.  This happens even without putting the
"/X" param. on any BUFFERS=, etc. or drivers or INSTALL=FASTOPEN().

Confused as ever,

John Wright      //////////////////     Phone:  902-424-3805  or  902-424-6527
Post: c/o Dr Pat Lane, Biology Dept, Dalhousie U, Halifax N.S., CANADA B3H-4H8 
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-- 
John Wright      //////////////////     Phone:  902-424-3805  or  902-424-6527
Post: c/o Dr Pat Lane, Biology Dept, Dalhousie U, Halifax N.S., CANADA B3H-4H8 
Cdn/Eannet:lane@cs.dal.cdn  Uucp:lane@dalcs.uucp or {uunet watmath}!dalcs!lane
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