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From: plim@hpsgpa.HP.COM (Peter Lim)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Desqview and EMS 4.0
Message-ID: <340040@hpsgpa.HP.COM>
Date: 30 Nov 89 04:54:16 GMT
References: <5555@cps3xx.UUCP>
Organization: HP Singapore IC Design Ctr
Lines: 52

> When operating in the Desqview environment, is EMS 4.0 treated like
> EEMS?
>
Yes if you have true hardware EMS 4.0. Those software emulators are no
bloody good. True EMS 4.0 means that you can switch EMS pages in and
out of the address space below the 640K as well.

> I have an 80286, and I need to know if it is possible to multitask
> beyond 640K. Currently, Desqview swaps programs in and out of low
> memory. It sure would be nice to run Microsoft C (~380K) and a text
> editor (~200K) with background compilation.
> 
Well, technically speaking with EMS 4.0, what you want is not "multitask
beyond 640K". What you actually want is multitask with multiple copies
of below 640K ! You will need to "backfill" your motherboard memory from
256K to 640K. What this means is that you'll need to plug out all your
motherboard memory above 256K, set the motherboard switches (or CMOS
RAM) to say that you have only 256K of RAM -- unless you are the very
few person who own an AST AT motherboard which can do bank switching
with memory below 640K  :-). Then, you'll have to instruct DesqView (or
was it the EMS driver ??) to "backfill" the empty space from 256K to
640K. From then on, you should be able to do fairly true multitasking in
the memory range from 256K to 640K (which is about 384K; so I wonder if
your Microsoft C partition will fit ??). Its all in the DesqView manual.

> Am I asking too much of an 80286 under DOS? Or will I have to upgrade to
> an 80386?
> 
No, you are not asking too much from 80286 under DOS provided you have
true hardware EMS 4.0. But then as I said earlier, you will only get 384K
to multitask in. Of course everything will work better if you have an
80386 machine.

What I said above are pure logical reasoning, I have not done it myself.
I have an 80386 machine, and with QEMM-386 I load all my TSR into memory
above 640K leaving only DOS below 640K. When I run DesqView, I get about
512K of memory to multitask in, which is great !

Hope that helps.  Happy multitasking !


Regards,
Peter Lim.
HP Singapore IC Design Center.

      E-mail address:              plim@hpsgwg.HP.COM
      Snail Mail address:          Peter Lim
                                   Hewlett Packard Singapore,
                                   (ICDS, ICS)
                                   1150, Depot Road,
                                   Singapore   0410.
      Telephone:                   (065)-279-2289