[comp.windows.ms] Is windows 286/386 using expanded memory?

ch@hpislx.HP.COM (Chuck Heller) (08/15/89)

How can I tell if MS-Windows is using expanded memory itself?

We have an MS-Windows application that uses expanded memory directly,
so we have to invoke it as

	win[386] /N our_application

since the /N will tell windows to NOT use expanded memory itself.
If windows tries to use expanded memory, we compete and crash.
If I could tell that windows was using expanded memory, then we could
set a flag and use only conventional.

I know that Excel uses expanded memory directly, so there must be some
answer.

As another thought, what does windows use expanded memory for, and can
we predict when it is going to use it?  I heard that it uses it for
swapping applications in & out.  If that is the only use, then certainly
our calls to CreatePen would not need to flush our expanded memory buffers,
whereas if windows might create the pen data structure in expanded memory,
then we would need to flush our expanded memory buffers before ANY windows
call.

Any insight would be appreciated.

Chuck Heller
Hewlett-Packard

brent@well.UUCP (Brent Southard) (08/17/89)

In article <3000001@hpislx.HP.COM> ch@hpislx.HP.COM (Chuck Heller) writes:
>How can I tell if MS-Windows is using expanded memory itself?

  I'm not sure, but you shouldn't have to.

>We have an MS-Windows application that uses expanded memory directly...
>If windows tries to use expanded memory, we compete and crash.

  This isn't completely true.  A Windows application is free to make any use
  of SMALL FRAME EMS (LIM 3.2), but may not invoke any of the new (4.0)
  functions except for (I believe) function 18, Reallocate Pages.  As long
  as you follow these rules, you will not conflict with Windows or other
  applications.

Good luck,
Brent
-- 
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ch@hpislx.HP.COM (Chuck Heller) (08/21/89)

Thanks to "philba" for pointing out the solution:

"rc -l" tells windows that your application uses expanded memory directly.