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- Chapter 2
-
- Changing A Program's Information
-
- ~Subhead~ Optimizing 80386 Performance
-
- Change a Program options which affect program performance on an 80386 or
- i486 are as follows:
-
- ~Item~ Writes text directly to the screen, which tells DESQview 386 whether
- a non-virtualized program is well-behaved or not.
-
- ~Item~ Virtualize text/graphics, which tells DESQview 386 whether to run
- text, CGA, MCGA, Hercules, EGA and VGA programs in a small window.
-
- ~Item~ Runs in background, which tells DESQview 386 to allow a program to run
- in the background.
-
- ~Item~ Share CPU when foreground, which tells DESQview 386 whether to run
- other programs in the background when this one is executing in the
- foreground.
-
- ~Item~ Share EGA when foreground/zoomed, which tells DESQview 386 whether to
- allow other EGA programs to use the EGA hardware when this one is executing
- full screen in foreground.
-
- ~Item~ Protection level, which tells DESQview whether to initiate extra
- protection against possible program misbehavior.
-
- ~Item~ Uses its own colors, which tells DESQview what color palette to invoke
- when the program is running in foreground.
-
- If a program is listed on DESQview's Add a Program menu ~dash~ or if you
- have a DESQview Program Information File (DVP) for the program- ~dash~
- DESQview has already set default program information for your program.
- DESQview's default settings, which affect 80386 performance, are as follows:
-
- ~Begin Table~
- Option Setting
- Writes text directly to the screen Yes
- Virtualize text/graphics Yes
- Runs in background Blank
- Uses its own colors No
- Share CPU when foreground Yes
- Share EGA when foreground/zoomed No
- Protection level 0
-
- ~End Table~
-
- If you wish to change these default settings, then you must use DESQview's
- Change a Program to modify them.
-
- NOTE: The changes you make to a program's information file do not apply to
- a program already running when you used the Change a Program command. They
- only apply the next time you start up the program (from the Open Window
- menu). You can use the Tune Performance command to temporarily change some
- of these settings for programs currently running.
-
- When you change a program's information, the old DESQview Program
- Information File (DVP) for the program is saved as a backup file (BAK) and
- then a new DVP file is created containing the changed information.
-
- ~Subhead~ When a Program Writes Directly to Screen
-
- When your program displays information on the screen, it either does so
- using DOS or the BIOS (and is thus known as "well-behaved"), or it writes
- directly to the screen (and is known as "misbehaved"). "Well-behaved"
- programs run in DESQview windows ~dash~ on 8088, 8086, 80286 and 80386 PCs.
- "Misbehaved" programs write inside AND outside of the DESQview window area
- and therefore, require you to use them full screen.
-
- To find out whether or not your program can run in a small window usually
- requires experimentation. First set the Writes text directly to screen option
- to No (N) and the Virtualize text/graphics option to No (N). Then run your
- program in a small window. If the program writes outside of the DESQview
- window area, then it writes directly to the screen. You must then change the
- Writes text directly to screen option setting to Yes (Y).
-
- With QEMM-386 DESQview can run all text programs that write directly to the
- screen in a DESQview window. For DESQview to do this you must set the
- Virtualize text/graphics option to Yes (Y). See below.
-
- NOTE: If your program runs in a small window normally, you get the best
- performance when you set Writes text directly to the screen to No and set
- Virtualize text/graphics to No.
-
- ~Subhead~ Virtualizing Text & Graphics
-
- When running DESQview 386 on an 80386 PC, any text, CGA, Hercules, EGA or
- VGA program can run in a "small window", even if it is not "well-behaved".
- DESQview's ability to run all programs in small windows is called
- "virtualization". For performance reasons, you can control what DESQview
- virtualizes.
-
- The Virtualize text/graphics (Y, N, T) option specifies, when Yes, that
- DESQview should keep the program from writing directly to the screen under
- all circumstances. The program can then display its information in DESQview
- windows and run in background.
-
- When you specify No, DESQview's action is dependent upon how you set the
- Writes text directly to screen option. If your program writes directly to the
- screen, DESQview will not run your program in a small window. If your program
- does not write directly to the screen, DESQview will run the program in a
- small window.
-
- When you specify (T), for text only, DESQview will virtualize the screen
- when your program is in text mode only. If your program switches from text
- mode to graphics mode, the screen virtualization will stop. This option
- allows a program to run in a small window when in text mode, but use the
- screen directly when in graphics mode. Text mode virtualization causes very
- little performance degradation, whereas graphics virtualization can affect
- performance considerably ~dash~ especially on EGA displays.
-
- ~Subhead~ Sharing the Processor
-
- If you want maximum performance in your foreground program, you do not want
- other programs to be running in background.
-
- The Share CPU when in foreground option specifies, when Yes (Y), that you
- allow other programs to run in background when this program is executing in
- the foreground.
-
- If you enter No (N) to Share the CPU, DESQview will freeze all programs
- running in background when the foreground program is executing.
-
- When the foreground program is not executing (for example, waiting for a
- keyboard character), then background programs will be allowed to run.
-
- You can dynamically change this option, using DESQview's Tune Performance
- command.
-
- ~Subhead~ Sharing the EGA
-
- If you want maximum performance in your foreground graphics program, you do
- not want other programs to be sharing your EGA hardware.
-
- The Share EGA when in foreground/zoomed option specifies, when Yes (Y), for
- DESQview to allow other EGA graphics programs to run in background. If you
- enter no (N) to Share the EGA, DESQview will freeze EGA programs running in
- background when your program is zoomed. If you enter yes (Y), all EGA
- programs will run more slowly.
-
- You can dynamically change this option, using DESQview's Tune Performance
- command.
-
- ~Subhead~ Protecting Programs from Each Other
-
- DESQview uses the 80386 processor's protection capabilities to give you
- protection against misbehaved programs. Protection can result in some
- performance degradation of your program.
-
- DESQview will exercise more protection the higher the protection level
- selected. Selecting 0 tells DESQview not to set up any special protection
- around your program. If you know your program is reliable and works without
- crashing, we strongly suggest that you do not set up any protection.
-
- If DESQview 386 detects that the program is trying to do something which
- might damage DESQview, DOS, or other programs, DESQview will post an error
- message (prior to the damage being done) describing in technical terms the
- action that seemed dangerous. You may then abort the program, or turn off
- DESQview's protection and let the program proceed on its dangerous course.
- Sometimes you will be given a third option, of allowing this one violation to
- occur, but keeping the protection in place to detect further violations.
-
- Typically, you should abort the program if you get a protection violation.
- Then, try increasing the memory size for the program and try it again. If the
- violation no longer occurs, then the program probably required more memory
- than you had previously given it, but it failed to detect that it had
- insufficient memory. You might want to inform the program developer of this.
-
- If the protection violations continue, then perhaps the program has a bug in
- it, or perhaps it is doing something which, although potentially dangerous,
- is really all right. You can try lowering the protection level (or setting it
- to 0) and hope for the best.
-
- ~Subhead~ Using a Program's Colors
-
- The Uses its own colors option specifies, when Yes, that the program has its
- own color scheme and that you wish to use this color scheme instead of the
- one that DESQview normally provides for the window (See Appendix A of the
- DESQview manual). The DESQview color scheme uses the standard IBM palette.
-
- If, outside of DESQview, you like the colors your program uses, you should
- select Yes (Y) for the Uses its own colors option. If you'd like DESQview to
- display your program using colors from the DESQview palette, then you should
- select No (N).
-
- Graphics programs often have their own palette ~dash~ chosen by the
- developer. So that your graphics program has the same look and feel outside
- and inside DESQview, DESQview will use the palette of your graphics program
- when the program is zoomed to full screen.
-
- As you run multiple graphics programs in small windows in DESQview 386, you
- will notice that your programs often change colors ~dash~ when you bring up
- the DESQview menu or when you switch windows. The reason is that DESQview
- sets the entire display according to the palette specified by the foreground
- program.
-
- Two graphics programs, with palettes different from the IBM palette, are
- Microsoft Windows and Digital Research's GEM. Not only have these two
- programs redefined the palette ~dash~ but you'll notice that when you have
- Ventura Publisher (a GEM program) and Microsoft Excel (a Windows program) on
- the screen at the same time in small windows, switching to Excel will cause
- Ventura to change from black characters on a white background to white colors
- on a black background.
-
- If you find that the graphics programs in background windows are unreadable
- or you are bothered by the colors, you can fine-tune the colors of
- DESQview's palette and menus.
-
- To fine-tune the colors of your programs' colors and of DESQview menus, you
- have the following DESQview tools:
-
- ~Item~ A DESQview palette program (DVPAL.COM) is included on your DESQview
- diskette and can be added to your Open Window menu by selecting "DESQview
- Pallette" from the Add a Program menu. This palette program lets you change
- the DESQview palette used in DESQview menus and used by those programs with
- No selected in the Uses it own colors option.
-
- ~Begin footnote~
- You will have to add DESQview Palette to DESQview's Open Window menu using
- the Add a Program command.
- ~End footnote~
-
- Using the DESQview palette utility, you can create you favorite palette by
- choosing the intensity of blue, green and red in each color of the palette,
- restore the original DESQview palette, make the DESQview palette the same as
- the GEM or Windows palette, load and save palettes, and set blinking for on
- or off.
-
- ~Begin footnote~
- Before using DESQview Palette, use Change a Program to set the Uses it own
- colors option to No and the Virtual text/graphics to Yes for the graphics
- programs whose colors you wish to change. Then open these graphics programs
- and put them in small windows so that you can see how their colors change as
- you change the palette.
- ~End footnote~
-
- ~Item~ DESQview Setup, Advanced Option, Colors lets you change the color
- scheme of each text window displayed using the DESQview palette and change
- the color scheme of DESQview's menus.
-
- If you change the DESQview palette (using the above palette program), so
- that it is the same as Microsoft Window's palette, DESQview's menus will turn
- red. You can make these DESQview menus blue again by using the Colors option
- in DESQview Setup.
-
- ~Subhead~ Running Programs in Background
-
- The Runs in Background option tells DESQview whether you want the program to
- run in the background, while you are working in another program. If this
- option is blank, DESQview will automatically determine if the program can run
- in background without disturbing the screen. However, if Writes text directly
- to screen is Y, then the program will not be allowed to run in background
- unless Virtualize is set to T or Y.
-