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From: phil@brahms.amd.com (Phil Ngai)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: 386SX and EMS 4.0
Message-ID: <1990Oct23.013403.28907@amd.com>
Date: 23 Oct 90 01:34:03 GMT
References: <16508@shlump.nac.dec.com> <1990Oct20.204053.20116@msuinfo.cl.msu.edu> <48848@bigtex.cactus.org>
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In article <48848@bigtex.cactus.org> james@bigtex.cactus.org (James Van Artsdalen) writes:
|In <1990Oct20.204053.20116@msuinfo.cl.msu.edu>, draper@cpsin2.cps.msu.edu
|	(Patrick J Draper) wrote:
|
|> I thought that all access to EMS was through the protected mode, and
|> that even if you had a C&T chipset it didn't change things.
|
|Not true.  EMS has nothing to do with protected mode.  QEMM & 386^max

As a matter of fact, EMS was invented for the 8088, which doesn't
even have a protected mode.

|kludge EMS support by using the pager in the 386.

I wouldn't call it a kludge. I would call the incomplete implementations
offered by C&T and the like a kludge.

|> Also I believe that the software emulation of EMS on a 386 machine is
|> faster than using the C&T chipset because the 386 can switch between
|> real and protected mode very quickly compared to a 286.

C&T implements EMS in hardware so there is no issue with the time
it takes to switch from real to protected mode.

|In addition, QEMM and such things have serious compatibility problems.

Actually, it is C&T that has serious compatibility problems with
things like DESQVIEW.

|You're always better off with hardware support if you have it because
|(1) it's net faster and (2) it's more compatible and less like to
|cause the floppy drive to fail or something.

If you're saying a 286 with C&T is better than a 386 with QEMM or
386Max, I disagree.

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