Windows 3.1 Resource Kit SYSTEM.INI [386ENH] Section A-L

SUMMARY

The information in this article can be found in the SYSINI.WRI file in the Microsoft Windows Resource Kit for the Microsoft Windows operating system version 3.1. The SYSINI.WRI file can be viewed in Microsoft Windows Write. Write is an application contained in the Windows Accessories Group.

The [386Enh] section of the SYSTEM.INI file contains information specific to running Windows in 386-enhanced mode, including information used for virtual-memory page swapping.

MORE INFORMATION

The [386Enh] section can contain the following settings: ____________________________________________________________ 32BitDiskAccess=<boolean> Default: Off if your hard disk is capable of supporting 32-

          bit disk access. Otherwise, this setting is not
          present in the SYSTEM.INI file.

            Panel window. If this setting is not present in
            the SYSTEM.INI file, the 32-bit Disk Access
            check box will not appear in the Control Panel
            Virtual Memory dialog box.

          information about the A20 enable count, see your
          Extended Memory specification).

            should never need to change this setting.)

          to run in exclusive full-screen mode, overriding
          all contrary settings in the applications' program
          information files (PIFs). Enabling this setting
          might prolong the length of the Windows session
          when you are running network and memory-resident
          software that is incompatible with Windows.

          keyboard interrupt after it processes an ALT
          interrupt.  Some applications expect a slower
          processing rate than Windows in 386 enhanced mode
          normally uses. Increase this value if such an
          application has trouble handling the ALT key.

          pasting any characters after the ALT key has been
          released. Some applications may require more time
          for recognition of the ALT keystroke.

          expanded memory used by all Windows and non-
          Windows applications into memory (instead of
          swapping it to disk) and overrides the non-
          Windows application PIF settings for EMS Memory
          Locked. Set this value to True if you are using a
          disk cache program that uses expanded memory.

          extended memory used by all Windows and non-
          Windows applications into memory  (instead of
          swapping it to disk), and overrides non-Windows
          application PIF settings for XMS Memory Locked.

            should never need to change this setting).

          applications should be restored by Windows or the
          applications themselves when they become active.
          If enabled, Windows saves the display information
          for a non-Windows application in memory when you
          switch away from the application. When you switch
          back to the application, Windows uses this
          information to restore the screen. If disabled,
          the application must restore its own display by
          repainting the screen. This requires less memory,
          but can slow down performance since Windows can
          usually restore the screen faster.

       only applications that notify Windows that they can
       update their own screen automatically when Windows
       initiates a display update call.

          non-Windows application or to Windows to prevent
          the application from attempting to access the
          display (which might corrupt the display of a
          different application). This notification can be
          sent while switching to a different application or
          when attempting to access the actual display. If
          disabled, Windows sends a notification when
          switching between applications. Disable this
          setting if you are using a display that has
          special hardware, (for example, 8514 and TIGA). If
          you are using a VGA display, enabling this setting
          should work in most cases.

          font used for non-Windows applications with a
          display of 40 columns and 25 or fewer lines.

            prompt. Change the Codepage or Display
            setting.

          font used for non-Windows applications with a
          display of 80 columns and 25 or fewer lines.

            prompt. to change the Codepage or Display
            setting.

          to avoid snow appearing on an IBM CGA display
          device.

          connected serial port. These values are used by
          Windows to determine how to arbitrate requests for
          the use of a device by more than one application,
          at least one of which is a non-Windows
          application. If the value is -1, Windows will
          display a warning message that asks you which
          application should be given control of the port.
          If the value is zero, any application can use the
          device at any time. If the value is a positive
          integer less than 1,000, this value represents the
          number of seconds after an application stops using
          the device before another application can use the
          same device.

            Panel window.

          in the BIOS data area for COM1, COM2, anc COM4.

          port adapter you are using. Check you hardware
          documentation for the appropriate value.

       enhanced mode.

            Ports option in Control Panel.

          allow a virtual machine to process a COM
          interrupt. If a communications application is
          losing keyboard characters on the display, you can
          try increasing this value.

          on the corresponding serial port will place in the
          buffer. Before changing one of these settings, see
          the corresponding COMxProtocol setting to make
          sure that it has the proper value. Buffering may
          slow down communications on a port, but might be
          necessary to prevent some communications
          applications from losing characters at high baud
          rates. The size of the buffer required will depend
          on the speed of the machine and the application's
          needs.
To change:      Use Notepad to edit the SYSTEM.INI file.

          (VCD) uses its own copy of the serial communica-
          tions driver's interrupt handler. This improves
          performance of your COM ports. Enable this setting
          if you are using a Windows 3.0 serial communica-
          tions driver. Disable this setting if you are
          using the standard Windows 3.1 serial communica-
          tions driver.

          16550 Universal Asynchronous Receiver Transmitter
          (UART) should be enabled (true) or disabled
          (false). If a serial port does not have a 16550
          UART, this setting is ignored.

       and enhanced modes.

          and EISA machines. COM1Irq=4; COM2Irq=3;
          COM3Irq=3; COM4Irq=3 for MCA machines

          the device on the corresponding serial port. Check
          your hardware documentation for the appropriate
          value. If there is a hardware conflict between
          ports, set this value to -1 to disable input for a
          COM port.

       enhanced mode.

            Ports option in Control Panel.

          False for all other machines

          between multiple serial ports or with other
          devices. Enable this setting if your machine uses
          the same interrupt for COM3 or COM4 as it does for
          COM1 or COM2.

          entry other than XOFF)

          should stop simulating characters into a virtual
          machine after the virtual machine sends an XOFF
          character. Set the value for a port to XOFF if a
          communications application using that port is
          losing characters while doing text transfers at
          high baud rates. Windows will resume simulating
          characters when the virtual machine sends another
          character after the XOFF character. Leave this
          setting disabled if the application is doing
          binary data transfers; enabling this switch might
          suspend binary transmissions. Windows will not
          check for XOFF characters if this setting is blank
          or set to anything other than XOFF. If the
          application continues to lose characters after
          this setting is properly set, try increasing the
          corresponding COMxBuffer value.

          your system configuration.)

          Windows in 386 enhanced mode. This value can
          appear in two ways: either the name of a specific
          virtual device file, or an asterisk (*) followed
          immediately by the device name. The latter case
          refers to a virtual device that is in the
          WIN386.EXE file. Filenames usually include the
          .386 extension. Multiple device lines are required
          to run Windows in 386 enhanced mode.

          your system configuration.)

          with Windows in 386 enhanced mode.

            Group window.

          access (DMA) buffer memory should be in the first
          1MB of memory (above 640K, if possible) in order
          to be compatible with 8-bit bus master cards.

          be reserved for the direct memory access buffer
          (DMA). This memory will be allocated above 640K,
          if possible. Windows in 386 enhanced mode will
          default to a DMA buffer size that will handle disk
          access.

          message box appears, with instructions on how to
          exit and switch away from the MS-DOS prompt.
          Disable this setting if you do not want to see the
          message.

          memory between B000:0000 and B7FF:000F is used by
          the general system unless a secondary display is
          detected. Enable this setting if you are using a
          VGA-based color display and want EMM386.EXE to
          include this address space as an upper memory
          block (UMB). In addition to enabling this setting,
          you must include the i= option in the
          device=EMM386.EXE command line in your CONFIG.SYS
          file as follows:

                                device=EMM386.EXE i=B000-B7FF

          If this setting is disabled, the address range is
          available on EGA systems, but not on VGA systems,
          because the VGA display device supports monochrome
          modes, which use this address space.

          your system configuration.)

          used with Windows in 386 enhanced mode.

          font used for non-Windows applications with a
          display of 40 columns and more than 25 lines.

            prompt. Change the Codepage or Display setting.

          font used for non-Windows applications with a
          display of 80 columns and more than 25 lines.

            prompt. Change the Codepage or Display setting.

          goes with its own EISADMA setting.)

          channel for Extended Industry Standard
          Architecture (EISA) machines only. This setting's
          value can take one of two forms. If you disable
          this setting, Windows will treat the machine as
          non-EISA, therefore avoiding all EISA-related
          logic. You can try disabling this switch if you
          cannot run Windows in 386 enhanced mode on your
          EISA machine. If you are using an EISA machine,
          you can specify the default transfer size for one
          or more DMA channels. The channels can operate in
          the following modes: 8-bit (8), 16-bit specified
          in words (16w), 16-bit specified in bytes (16b),
          or 32-bit (32). If you are not using an EISA
          machine, Windows will ignore this setting.

          scan to find unused address space. This has the
          side effect of turning off the RAM and ROM search
          code for the range. The range (two paragraph
          values separated by a hyphen) must be between A000
          and EFFF. This scanning can interfere with some
          adapters that use the same memory area. The
          starting value is rounded down and the ending
          value is rounded up to a multiple of 16K. For
          example, you could set EMMExclude=C800-CFFF to
          prevent Windows from scanning the addresses
          C800:0000 through CFFF:000F. You can specify more
          than one range by including more than one
          EMMExclude line.

          treat as unused address space regardless of what
          may be there. EMMInclude takes precedence over
          EMMExclude if you specify ranges that overlap. The
          range (two values separated by a hyphen) must be
          between A000 and EFFF. The starting value is
          rounded down and the ending value is rounded up to
          a multiple of 16K.  For example, you could set
          EMMInclude=C800-CFFF to ensure that Windows can
          use the addresses C800:0000 through CFFF:000F.
          You may specify more than one range by including
          more than one EMMInclude line.

          page frame will begin when Windows in 386 enhanced
          mode cannot find a suitable page frame. Allows an
          EMM page frame in an area containing some unused
          RAM or ROM. For example, you could set
          EMMPageFrame=C400 to start the page frame at
          C400:0000.

          mapping as expanded memory. The default value
          allocates the maximum possible amount of system
          memory as expanded memory. Specify a value for
          this setting if you run an application that  \
          allocates all of the available expanded memory. If
          this is the case, you cannot create new virtual
          machines. If this value is zero, then no expanded
          memory will be allocated, but the EMM driver will
          be loaded. To disable EMM and prevent the EMM
          driver from loading, use the NoEMMDriver setting.

          standard mode.

          receives messages anytime a non-Windows
          application creates, renames, or deletes a file.
          If disabled, a virtual machine can run
          exclusively, even if it modifies files. Enabling
          this setting can slow down system performance
          significantly.

          to be global to the system. The default setting
          for all devices is global. However, certain
          virtual devices might specify that a DOS device be
          local (for example, MS$MOUSE). Use this setting to
          override that local specification. The <device-
          name> value must exactly match the case of the
          device name, or setting will not work. (Most
          device names are in all capital letters, therefore
          this value must usually be in all caps.)

          channel computers or computers that use Direct
          Memory Access (DMA) channel 3 (unless you are
          using SMARTDrive and double-buffering is turned
          on. In this case the default is 0.)

          buffer. If you are using SMARTDrive and double-
          buffering is turned on, this amount is determined
          automatically. You may need to change this value
          if you are using a hard disk that supports DMA and
          are not using SMARTDrive, or if you do not have
          double-buffering turned on.

          idle virtual machines after the specified number
          of seconds have elapsed. If a virtual machine does
          not use timer interrupts (Int 8 or Int 1Ch),
          Windows will not usually force timer interrupts
          into a virtual machine unless it is active. This
          setting forces the timer interrupts to occur. The
          value for this setting is rounded  down to
          the lowest power of two (for example, 1, 2, 4, 8,
          16, 32, 64).

          mode, even when there is  an unknown expanded
          memory manager (EMM) running. This can cause the
          system to fail if memory-resident software was
          using EMM before Windows was started. Enable this
          setting only if no such software is installed or
          you are sure will not be active when you are
          running Windows. This setting applies only to
          expanded memory managers servicing physical EMS
          hardware; Windows will not disable unrecognized
          80386 expanded memory emulators.

          applications when memory-resident software has the
          InDOS flag set. Enabling this setting is necessary
          if the memory-resident software needs to be in a
          critical section to do operations off an INT21
          hook, but will slow down system performance
          slightly.

          handle INT28h interrupts used by memory-resident
          software. Some networks do internal task switching
          on INT28h interrupts. These interrupts might hang
          some network software, indicating the need for an
          INT28h critical section. If you are not using such
          software, you might improve Windows' task
          switching by disabling this setting.

          this setting if your system hangs when accessing a
          floppy drive. Or make sure your system accesses
          the floppy drive before starting Windows.

          your system configuration.)

          with Windows in 386 enhanced mode.

            Group window.

          application runs with  increased priority when it
          receives a keystroke. You can use this setting to
          increase the response to keystrokes when several
          background applications are running.

          pasting keyboard input after the keyboard buffer
          is full. Some applications might require more than
          .2 seconds.

          after simulating a keystroke into a virtual
          machine. You can set this value to 0 to speed up
          keyboard input, but some applications might slow
          down significantly.

          INT 16 call should return a status of empty for
          the keyboard buffer after pasting a carriage
          return before pasting another character. When
          Windows pastes information from the Clipboard to a
          non-Windows application, it must first paste the
          information to the BIOS keyboard buffer before
          pasting it into the application. This setting is
          used to slow down fast pasting from the Clipboard
          to the keyboard buffer so that the application can
          handle all incoming characters from the buffer. If
          you seem to lose characters, or if the screen does
          not update often enough while pasting information
          from the Clipboard, increase this value. This
          setting is related to KeyPasteSkipCount.

          before pasting any characters after a key has been
          pasted. Some applications might require more time
          than .003 seconds for recognition of a keystroke.

          INT 16 call should return a status of empty for
          the keyboard buffer before pasting another
          character. When Windows pastes information from
          the Clipboard to a non-Windows application, it
          must first paste the information to the BIOS
          keyboard buffer before pasting it into the
          application. This setting is used to slow down
          fast pasting from the Clipboard to the keyboard
          buffer so that the application can handle all
          incoming characters from the buffer. If you seem
          to lose characters, or if the screen does not
          update often enough while pasting information from
          the Clipboard, increase this value. This setting
          is related to KeyPasteCRSkipCount

          application to make the necessary BIOS calls for
          reading keyboard input before Windows will change
          from the fast paste (INT16h) to the slow paste
          (INT9h) mechanism.

          computers

          (VKD) should support PS/2 8042 commands that
          implement password security. This setting only
          applies to 8042 keyboard controllers that are
          compatible with the PS/2 computer.

          computer using a keyboard controller command. On
          some computers this method is unreliable. If your
          computer hangs while rebooting, then disable this
          setting. In this case, Windows will quit and then
          display a prompt to press CTRL+ALT+DEL a second
          time.

          set Local=CON. See "Purpose.")

          local to each virtual machine. The <device-name>
          value must exactly match the case of the device
          name, or this setting will not work. (Most device
          names are in all capital letters, therefore this
          value must usually be in all caps.) If a device
          driver is local, a separate copy of it will exist
          in each virtual machine, and each will keep
          different state information. Most device drivers
          will not function properly when this setting is
          used. An exception is CON, the DOS console device,
          which should be local to avoid filling a buffer
          with input from multiple virtual machines.

          Memory Block) area is used when Windows in running
          on MS-DOS version 5.0. If disabled, then Windows
          uses all of the UMB area, leaving no extra UMB
          space available for Virtual Machines. If enabled,
          then Windows does not use all of the extra UMB
          area. In this case, UMB area is available locally
          to each Virtual Machine.

          quit applications that cause an unrecoverable
          errors in 386 enhanced mode, without restarting
          Windows. If this setting is enabled, you can quit
          the applications. If this setting is disabled,
          pressing CTRL+ALT+DEL will restart your entire
          system (as it normally does.)

Note: These settings apply to Windows version 3.0 only. If

       you have upgraded to Windows 3.1, these settings may
       still appear in your SYSTEM.INI file, but will have
       no affect.

          paging rate sweep  frequency. The low paging rate
          sweep frequency is computed by multiplying the
          value for LRUSweepFreq by the value specified for
          this setting. Values between 1 and 65535 may be
          used.

            should never need to change this setting).

          Manager stays at high rate with no paging before
          switching to low rate, and the length of time the
          Memory Manager stays at low rate with no paging
          before turning the Least-Recently-Used (LRU) Sweep
          off.

            should never need to change this setting).

          also the high paging rate sweep frequency.

            should never need to change this setting).

          value of LRUSweepReset by the value of
          LRUSweepFreq)

          on each pass. The value must be at least 1.

            should never need to change this setting).

          sweeper should be turned on. When the number of
          free pages drops below this value, the sweeper is
          turned on.

            should never need to change this setting).

          divided by 4 megabytes of pages. Therefore, the
          time to reset all ACC bits is: (number of pages in
          system+1023/1024) where 1024 pages = 4megabytes.
          The minimum value is 100.

            should never need to change this setting).

Reference(s):

Microsoft Windows Resource Kit 3.1, SYSTEM.INI file