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Q72929: Windows Resource Kit HDC Memory Viewer and Windows 3.0

Article: Q72929
Product(s): Microsoft Windows 95.x Retail Product
Version(s): WINDOWS:3.0,3.0a
Operating System(s): 
Keyword(s): 
Last Modified: 04-OCT-1999

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The information in this article applies to:

- Microsoft Windows versions 3.0, 3.0a 
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SUMMARY
=======

The hDC Memory Viewer is a utility included as part of the Windows Resource Kit.
This utility gives you a graphic display of how your system's memory (including
extended and expanded memory) is being used. It also uses an icon to display the
amount of free memory you have available. The following is a description of how
Memory Viewer reports the memory usage under Windows.

MORE INFORMATION
================

The amount of memory use being reported in the DOS area includes the memory used
by any TSR (terminate-and-stay-resident) programs and drivers, including
SMARTDrive or RAMDrive.

When the Include Discardables check box is selected in the Options File menu in
the hDC Memory Viewer, it will display the sum amount of memory including code
segments that Windows has marked as "discardable." Not all the code segments
that an application requires are needed at any given moment. When these unused
code segments are marked as discardable, Windows can use that area of memory for
another applications. However, it must always save enough memory space so that
all the applications that are loaded can perform any potential functions that
they might call. This is where the "Swap Area" listed on the Memory Viewer comes
in; this is a common "ensure area" that Windows uses to ensure that all
applications have the potential memory that they may need.

Most Windows-based applications have a large portion of their code segment marked
as discardable; however, not all Window's-based applications do this.

The Memory Viewer has the option to display memory used by applications, system
libraries, system fonts, and device drivers. The memory reported in use by
system libraries (User, GDI, and so on) is an indication of how much system
resources are being used, but it requires some interpretation. The amount
reported for each library includes the data segment, any code segments, and any
objects on the local heap "owned" by that library. Any one of these items can be
up to 64K (thus the 64K limitation on system resources in Windows 3.0). When
combined, however, they could be a lot more -- this is why each of the libraries
can total 100K or more.

REFERENCES
==========

hDC Corp. Technical Support

"Windows Resource Kit," page 173

KBCategory: kbtool kbdisplay
KBSubcategory: win30

Additional query words: 3.00 3.00a 3.0a 3.0 WRK win30

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Keywords          :  
Technology        : kbWin3xSearch kbZNotKeyword3 kbWin300 kbWin300a
Version           : WINDOWS:3.0,3.0a

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