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- PCBTechnote : Maximizing Memory Available To Each DESQview Window
- Written by: Steve Catmull - CDC Tech Support
-
- Date : 02/16/93
-
-
- DISCLAIMER: The information provided in this document is provided as is
- without any warranty of any type or guarantee of fitness of use. The
- configuration detailed in this document have been tested, however
- results may vary from system to system and you assume full
- responsibility for trying any of the above suggestions on your system.
- It is suggested that before you attempt any of the suggestions listed,
- that you completely back-up your system.
-
- PCBoard is a registered trademark of Clark Development Company, Inc.
- QEMM and DESQview are trademarks of Quarterdeck Office Systems.
-
- *****************************************************************************
-
- One concern when running PCBoard nodes under DESQview, is the amount of
- memory available in each window that you open. If you do not have
- enough memory, then you may see one of the following messages in the
- upper right hand side of your screen:
-
- * Swapping...
- * Insufficient memory to open that program...
- * A non-swappable window is in the way.
-
- NOTE: When using communications programs like PCBoard, you should never
- see the first message (Swapping). That message informs you that
- the program is swapping out of memory and that it *will* stop
- executing at this point. Obviously, for a program like PCBoard
- which needs to always be running it would present a serious
- problem. The way around this is to go into DESQview's Setup
- program, select Performance, and then set "Allow Swapping of
- Programs" to "N".
-
- For the remainder of this document the following assumptions will be made:
-
- * 80386/80486 computer is being used
- * VGA or SVGA video card is installed
- * DESQview v2.4+ is being used
- * QEMM is being used as the memory manager.
-
-
- Determining How Big Your DESQview Windows Can Be
- ------------------------------------------------
-
- When you have DESQview loaded, you can open the Memory Status Window to
- see how much memory you have available for each window on your system.
- Below is a sample display of the Memory Status window:
-
-
- Total Total Largest
- Memory Available Available
-
- Common Memory 14336 8138 8128
-
- Conventional Memory 538K 71K 68K
-
- Expanded Memory 5024K 3456K -=> 528K <=-
-
-
- When you are looking at this display, you should look at the two
- right-hand bottom numbers. The larger of these two numbers is the
- largest size that the next DESQview window can be. In this example, you
- can see that 528K is the largest that the next window can be.
-
- NOTE: DESQview has a certain amount of overhead associated with each
- window that it opens. This depends on some of the options set in
- the PIF file. Keep this in mind when you view the Memory Status
- report. The numbers that it reports does not include any overhead
- figures.
-
-
- I Have More Memory Available At The DOS Prompt. What Happened?
- ---------------------------------------------------------------
-
- The fact that you need to keep in mind, is that you are no longer at the
- DOS prompt when you are in DESQview -- You are in a multitasker. This
- is an *important* fact to remember. What may increase the conventional
- memory that you have available at bootup may actually give you LESS
- memory per window in DESQview.
-
-
- How Can I Increase The Memory Available To Each Window?
- -------------------------------------------------------
-
- Ah, the age old question. Before you go any further, you need to
- understand how DESQview loads itself into memory. DESQview will first
- try to use HMA (1024K-1088K). If it needs more, it will then proceed to
- load itself into high memory (640K-1024K). If it still needs more
- memory then it will proceed to use conventional memory. The following
- list summarizes the order of memory that DESQview will use:
-
- 1. HMA (1024-1088K)
- 2. High Memory (640K-1024K)
- 3. Conventional Memory (0K-640K)
-
- Obviously, you want DESQview to load in either HMA or high memory if at
- all possible. All totaled up, that is about 448K of memory that
- DESQview could theoretically use. However, there are other factors that
- come into play. For example, your high memory may be partially used up
- by the following:
-
- * TSRs or device drivers loaded in AUTOEXEC.BAT and CONFIG.SYS
- * ROM or Adapter RAM for the hardware in your system.
- * Video memory
- * EMS Page Frame
-
- High memory is where you will want to do all of your fancy footwork. To
- begin, you will want to remove all "un-necessary" TSRs and device
- drivers. Some of the perennial favorites like DOSKEY and ANSI
- (DVANSI.COM) can be loaded as TSRs *after* DESQview is loaded.
-
- If you are still need more high memory then you have to enter sacrifice
- mode. In other words, from this point on, you will have to start
- sacrificing features of your machine to get more memory. Do not worry,
- it is not as bad as it sounds.
-
- The easiest change you can make is to add FRAME=NONE on your QEMM386.SYS
- command line. This will give you an additional 64K of high memory that
- you can use. What you just sacrificed was EMS memory. By setting no
- page frame, you disable EMS memory for your applications. However, most
- applications that support EMS also support XMS which you do not need a
- page frame for and consequently would still be available.
-
- If you *still* need more high memory, the next thing you could do is
- sacrifice your ability to use VGA graphics or VGA (80x50) text mode.
- This would allow you to gain 64K of high memory (or 64K of conventional
- memory if you use VIDRAM.EXE and the VIDRAMEMS option on your
- QEMM386.SYS command line.
-
-
- I've Heard There Are Other Ways To Get More Memory
- --------------------------------------------------
-
- Yes, may be able to get even more high memory by taking advantage of
- QEMM 6.x's Stealth mode and performing the analysis feature of QEMM.
- However, I prefer to use the methods listed before for two simple
- reasons:
-
- * They should work well on all 386/486 machines.
- * They can be less time consuming to incorporate.
-
- The choice is yours. You may decide that you really need VGA
- capabilities so that you can run DESQview in 30, 50, or 60 line mode.
- In this case, you could not use technique that disables VGA. Likewise,
- you may have a driver or other program which exclusively uses EMS
- memory. If that was the case, then you could not get rid of your page
- frame as described earlier.
-
- NOTE: If you do not use QEMM's Stealth mode, then take out DOS=HIGH
- in your CONFIG.SYS (if it is in there). If you are using Stealth mode,
- then experiment with DOS=HIGH to see if it increases or decreases your
- window size.
-
-
- THE RESULTS
- =============================================================================
-
- Obviously, you are probably interested in the numbers involved. The
- following shows the maximum window size that could be opened using the
- various techniques described above.
-
- ┌─────────────────────────────────────────────────────────────┐
- │ │
- │ CONFIG.SYS │
- │ ------------------------------------------ │
- │ DEVICE=C:\QEMM\QEMM386.SYS RAM │
- │ SHELL=C:\DOS\COMMAND.COM C:\DOS\ /E:768 │
- │ FILES=100 │
- │ FCBS=1,0 │
- │ BUFFERS=1 │
- │ │
- │ AUTOEXEC.BAT │
- │ ------------------------------------------ │
- │ C:\QEMM\LOADHI /R:4 C:\QEMM\BUFFERS=4 │
- │ C:\QEMM\LOADHI /R:2 C:WINDOWS\SMARTDRV.EXE │
- │ C:\QEMM\LOADHI /R:3 C:\DOS\SHARE │
- │ PROMPT $P$G │
- │ VERIFY=OFF │
- │ PATH=C:\DOS;C:\UTL;C:\PCB;C:\QEMM │
- │ C: │
- │ CD\DV │
- │ XDV │
- │ │
- │ Total Total Largest │
- │ Memory Available Available │
- │ │
- │ Common Memory 14336 10650 9324 │
- │ │
- │ Conventional Memory 586K 579K 572K │
- │ │
- │ Expanded Memory 5088K 2928K -=> 560K <=- │
- │ │
- │ │
- │ Summary: This is our base configuration. As you can see │
- │ there is 560K of memory available for each DESQview window │
- │ that was opened. │
- │ │
- └─────────────────────────────────────────────────────────────┘
-
-
- ┌─────────────────────────────────────────────────────────────┐
- │ │
- │ Adding FRAME=NONE to the QEMM386.SYS Command Line │
- │ │
- │ Total Total Largest │
- │ Memory Available Available │
- │ │
- │ Common Memory 14336 10698 10698 │
- │ │
- │ Conventional Memory 616K 609K 572K │
- │ │
- │ Expanded Memory 5024K 2912K -=> 560K <=- │
- │ │
- │ │
- │ Summary: Notice that the maximum size of the window │
- │ did not change. However, you now have 64K of additional │
- │ high memory that you could use to load CD-ROM drivers, │
- │ network drivers, etc. │
- │ │
- └─────────────────────────────────────────────────────────────┘
-
-
- ┌─────────────────────────────────────────────────────────────┐
- │ │
- │ Adding VIDRAMEMS to the QEMM386.SYS Command Line and │
- │ adding VIDRAM EMS ON to AUTOEXEC.BAT. │
- │ │
- │ │
- │ Total Total Largest │
- │ Memory Available Available │
- │ │
- │ Common Memory 14336 10698 10698 │
- │ │
- │ Conventional Memory 702K 694K 667K │
- │ │
- │ Expanded Memory 4960K 2848K 656K │
- │ │
- │ │
- │ Summary: Here the amount of memory for each DESQview │
- │ window really jumped. This is because we disabled VGA │
- │ graphics and used VIDRAM to extend conventional memory │
- │ all of the way to 736K. If you would rather have high │
- │ memory than the additional conventional memory, you can │
- │ just skip loading VIDRAM in your AUTOEXEC.BAT │
- │ │
- └─────────────────────────────────────────────────────────────┘
-
-
- Wrapping It All Up
- -----------------------------------------------------------------------------
-
- There are many different ways you can increase your high memory so that
- DESQview loads in such a way that you get larger windows. You need to
- determine the methods described earlier that will suit you best.
-
- The suggestions listed in this document are very simple modifications
- you can make to help increase your window size while still being able to
- load your PCBoard nodes. You should really contact Quarterdeck Office
- Systems (the makers of DESQview and QEMM). They would know best as far
- as to what you can and cannot do with their software.
-
- The information that is contained in this document simply points out
- some things that we have experimented with to increase DESQview's window
- size.
-
- *****************************************************************************
-
-