PIF Settings Required to Run FoxPro for MS-DOS in Windows

• Microsoft FoxPro for MS-DOS, versions 2.0, 2.5, and 2.5a

SUMMARY

If problems occur when you are running Microsoft FoxPro or any other MS-DOS-based application in the Microsoft Windows environment, you may need to modify the Program Information File (PIF) that is created when the program is set up to run with Windows.

This article describes changes that may be required to run FoxPro in the Windows environment.

MORE INFORMATION

The PIF Editor is installed by Windows in the Main group. Choose Open from the File menu, and then select the PIF you want to edit. If no FoxPro PIF is listed, start with the default settings in the PIF Editor window.

Application Shortcut Keys

Shortcut keys ease the process of switching between applications. Assigning shortcut keys to commonly used applications eliminates the need to use the Task List or repeatedly press ALT+TAB to move to an application. For a shortcut key combination to be effective, the PIF and the application must have the same filename.

Choose shortcut key combinations carefully to avoid conflicts that may occur if the application or Windows has already reserved the chosen key combination for its own use. Valid shortcut keys must include the ALT or CTRL keys and another key. The SHIFT key can also be used in combination with the ALT and/or CTRL keys.

PIF Settings

In Windows 386 enhanced mode, selecting the Background Execution option in the PIF enables FoxPro to continue processing while the input focus is on another application. However, selecting this option may slow the execution of the "foreground" application, depending on the minimum time slice and priority settings. For more information, see Chapter 5 of the Windows "User's Guide."

The text below lists some of the PIF options and their recommended settings.

Optional Parameters: Listed parameters are automatically added to the filename when the user double clicks the application's icon. Include the -t, -k, and -e options.

Video Mode: Set it to TEXT.

Memory Requirements: This parameter lists the minimum memory that must be present before Windows will allow the application to run. Windows allocates all available memory addressed below 640K to an MS-DOS-based application. Set this parameter to 128K.

XMS Memory Parameters: This setting specifies the amount of LIM/AST extended memory that the application requires. Leave these settings at their default values.

Directly Modifies: This parameter indicates that the application requires control of specified system resources (like the COM ports or the keyboard). Do not change these parameters unless the application requires direct control over these (otherwise shared) resources.

No Screen Exchange: This parameter prevents the application from using the Windows Clipboard through the ALT+PRINT SCREEN or PRINT SCREEN keys.

Prevent Program Switch: This parameter conserves memory by preventing the user from switching away from the application to another.

Close Window on Exit: Select this option. When the user closes the application, Windows automatically closes the "container window" that it creates.

Reserve Short Cut Keys: This parameter prevents Windows from using shortcut keys that the application reserves for its own use. The available options are as follows:

  ALT+ESC           This key combination switches to the "next"
                    application.

  ALT+TAB           This key combination switches to the "next"
                    application.

  CTRL+ESC          This key combination activates the Windows Task List.

  PRINT SCREEN      This key copies an image of the screen to the Windows
                    Clipboard.

  ALT+PRINT SCREEN  Under Windows 3.0, this key combination copies an
                    image of the screen to the Windows Clipboard. Under
                    Windows 3.1, this key combination copies an image of
                    the active window to the Windows Clipboard.

Although these values are suggested, every machine configuration is different and the appropriate settings change accordingly. As with any system, the more memory available and the faster the microprocessor, the faster that Windows (and FoxPro) run.