Windows 3.0 SYSTEM.INI [386Enh] Section

• Microsoft Windows operating system versions 3.0, 3.0a

SUMMARY

The following information is contained in the Microsoft Windows version 3.0 SYSINI.TXT readme file. The Windows Setup program copies this file to the Windows 3.0 directory.

MORE INFORMATION

[386Enh] SECTION

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

The [386Enh] section can contain the following settings:

AllVMsExclusive=<Boolean> Default: false Purpose: If enabled, this setting forces all applications to run in

         exclusive mode, overriding all contrary settings in the
         applications' program information files (PIFs). Enabling this
         setting might prolong the life of network and memory-resident
         software that is incompatible with Windows.

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

         snow appearing on an IBM CGA display device.

         communications 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 the user 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.

To change: Choose the 386 Enhanced icon from the Control Panel window.

         you are using. The default values are as follows:

          Port       Default
          ----       -------
          COM1        3F8h
          COM2        2F8h
          COM3        3E8h
          COM4        2E8h

         Check your hardware documentation for the appropriate value.

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

         the specified communications port. The default values are as
         follows:

          Port       Default
          ----       -------
          COM1          4
          COM2          3
          COM3          4
          COM4          3

         Check your hardware documentation for the appropriate value.

         in 386 enhanced mode. This value can appear two ways: either
         the filename of a specific device driver, or an asterisk (*)
         followed immediately by the device name. The latter case
         refers to a virtual device that is in the WIN386.EXE file.
         Synonyms for device= are display=, keyboard=, network= and
         mouse=. Multiple device settings are required to run Windows
         in 386 enhanced mode.

         in 386 enhanced mode. This setting is a synonym to device=
         and exists to tell Setup which display device driver you are
         using.

         in the first 1 MB of memory in order to be compatible with
         8-bit bus master cards.

         direct memory access (DMA). Windows in 386 enhanced mode will
         default to a DMA buffer size that will handle disk access.

         between B000:0000 and B7FF:FFFF will be used by the general
         system unless a secondary display is detected. If this
         setting is enabled, this memory will be left unused and
         available for display adapters. If this setting is disabled,
         the address range will available on EGA systems but not under
         VGA systems, since the VGA display device supports monochrome
         modes, which use this address space.

         using as an EMM page. 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 C000
         and EFFF. Windows normally scans this area to find unused
         address space. This scanning can interfere with some adapters
         that use the same memory area. Values are rounded to a
         multiple of 16K. For example, you could set
         EMMExclude=C800-CFFF to prevent Windows from scanning the
         addresses C800:0000 through CFFF:FFFF. You may specify
         multiple memory ranges by using this setting more than once.

         as an EMM page 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 C000 and EFFF. Values are rounded to the nearest 16K.
         You may specify multiple memory ranges by using this setting
         more than once.

         begin only 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.

         mapping as expanded memory. The default allows all system
         memory to be allocated as EMM. You should specify a value for
         this setting if you run an application that allocates all of
         the available expanded memory. This will be apparent if, when
         you run the application, you can never create any new virtual
         machine. If this value is zero, then no expanded memory will
         be allocated, but the EMM driver will be loaded.

         messages anytime a non-Windows application creates, renames,
         or deletes a file. By disabling this setting , a virtual
         machine can be run exclusively even when it manipulates
         files.

         be global to the system. The default setting for all devices
         is global. But certain virtual devices might specify that a
         DOS device be local (for example, MS$MOUSE). Use this setting
         to override that local specification.

         E000:0000-EFFF:FFFF into a read. In rare cases, this might
         cause the system to fail because some software might, as a
         result, write over the system's shadow RAM if you have it in
         this area. If this happens, disable this setting and set
         EMMExclude to E000-EFFF.

         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
         started. Enable this setting only if no such software is
         installed or you are sure it will not be active when you are
         running Windows. Note: This only applies to expanded memory
         managers servicing physical EMS hardware; Windows will not
         disable 80386 expanded memory emulators.

         section to do operations off an INT21 hook. Enabling this
         setting assures that this will happen by preventing Windows
         from running other virtual machines when the memory-resident
         software has the InDOS flag set.

         Enable if you are using software that leaves IRQ9 masks,
         therefore hanging the system.

         in 386 enhanced mode. This is a synonym to device=.

         increased priority when it receives a keystroke. This setting
         can used to increase the response to keystrokes when several
         background applications are running.

         input after the keyboard buffer is full. Some applications
         may require a larger value than the default.

         after a key has been pasted. Some applications may require
         more time than the default for recognition of a keystroke.

         necessary BIOS calls after it reads keyboard input before
         Windows will setting from fast paste to slow paste keyboard
         input.

         virtual machine. This means a separate copy of the driver
         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.

         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 the user which application should
         be given control of the port. If the value is 0, 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.

To change: Choose the 386 Enhanced icon from the Control Panel window.

         enough buffer space to buffer it. Setting this setting to
         true may be useful if you do not want to use a lot of memory
         for buffers when running a network application that does
         large data transfers.

         manager will preallocate physical mappings. Use this setting
         if you are using a DOS device driver (such as an older
         version of RAMDrive that uses extended memory) that uses the
         INT15 MOVEBLOCK service to access memory allocated before
         Windows in 386 enhanced mode is started. Otherwise, if no
         memory is available, the MOVEBLOCK call may not be made.

         be allowed to run before other virtual machines may take
         over. A smaller value (such as 1 millisecond) will make
         multitasking appear smoother, but will diminish the overall
         system performance.

To change: Choose the 386 Enhanced icon from the Control Panel window.

         a temporary swap file. You would want to use this setting if
         your system's paging drive has less available space than
         Windows can use for paging. This setting has no effect if a
         permanent swap file exists.

         in 386 enhanced mode. This setting is a synonym for device=.

         Windows will attempt to allocate space in its global network
         buffer to receive the data. If there is insufficient space in
         the global buffer, Windows will normally fail the NetBIOS
         request. If this setting is enabled, Windows will attempt to
         save such a request by allocating a buffer in local memory
         and preventing any other VMs from running until the data is
         received and the timeout period (defined by NetAsynchTimeout)
         expires.

         to enter a critical section in order to service an
         asynchronous NetBIOS request. It is used only when
         NetAsynchFallback is enabled. This value can include a
         decimal (such as 0.5).

         0 on non-Micro Channel machines

         if a network has been installed. In this case, the buffer
         size is the larger value between this value and the value of
         DMABufferSize.

         enhanced mode allocates in conventional memory for
         transferring data over a network. All values are rounded up
         to the nearest 4K.

         is a synonym for device=.

         received.

         expanded memory driver. This differs from setting EMMSize to
         zero, which does not prevent the EMM driver from being
         loaded.

         disable this setting only if you need the disk space normally
         used for a temporary swap file.

         will allocate a temporary swap file. If the current drive is
         a network drive, the swap file will be created on the same
         drive as the SYSTEM.INI file. If both are network drives,
         paging will be disabled.

         2A signals. The default means Windows will consume these
         signals and therefore run more efficiently.

         allocates DOS transfer buffers below 640K. Leaving this
         setting disabled gives a non-Windows application more memory
         at the expense of EMS page frame space. Enable this setting
         only for an application that uses an EMS page frame.

         virtual machine rather than the current virtual machine.

         address space between F000 and 1 MB to find a special
         instruction that is used as a system break point. If this
         address space contains something other than permanently
         available ROM, you should disable this setting so that
         Windows will not use this space for a break point.

         the relative amount of processing time (based on the
         MinTimeSlice setting) given to all Windows applications
         running in the foreground relative to the time allocated to
         all non-Windows applications running in the background. The
         second number specifies the relative amount of processing
         time given to all Windows applications running in the
         background when a non-Windows application is running in the
         foreground. The range of numbers that can be entered is 1
         through 10000. The important value is the ratio of these
         settings to the corresponding settings in the program
         information files (PIFs) of the active non-Windows
         applications.

To change: Choose the 386 Enhanced icon from the Control Panel window.

         should be permitted to use. Leave this setting at zero to
         prevent Windows from gaining access to any expanded memory.
         Set it to -1 to give Windows all the available expanded
         memory that it requests.

         window.

         hard disk. Locking EMS memory can improve Windows
         performance, but it slows down the rest of the system.

         window.

         in order to start Windows. Leave this setting at zero if no
         Windows application uses expanded memory.

         window.

         processing time whenever a Windows application is active. If
         this setting is enabled and a Windows application is in the
         foreground, no non-Windows applications will run.

To change: Choose the 386 Enhanced icon from the Control Panel window.

         itself. The default value indicates that Windows can use as
         much of this space as it needs. You can try entering a
         positive value if there is not enough memory to run Windows
         in 386 enhanced mode.

         in order to start Windows. Setting this setting to -1 gives
         Windows all available conventional memory.

         being used in the system VM to remain locked in memory rather
         that being swappable out to disk. Because Windows handles
         this process, there is no known reason to enable this
         setting.

         allocate to DOS device drivers and memory-resident software
         in the system virtual machine. Set to -1 to give an
         application all the available extended memory that it
         requests.

         window.

         driver to the hard disk. Locking the XMS memory can improve
         an application's performance, but it slows down the rest of
         the system.

         window.

         reserved by the XMS driver in order to start Windows. Leave
         this setting at zero if there are no XMS users in the system
         virtual machine.

         window.

         adapter on AT architecture machines. Disable this setting if
         you are not using a token ring card and the search disables
         another device.

         codes to make them compatible with standard IBM scan codes.
         This setting is necessary only for keyboards that generate
         non-standard scan codes. This setting is used only for the
         Switcher Screen and message boxes.

         off for other machines

         trapping is enabled, the FIFO is never enabled. FIFO can
         interfere with DMA. Normally, you should disable this setting
         if there is a port conflict (port is 03F3h).

         to reserve some paragraphs of memory in each virtual machine
         (VM) prior to starting an application in the VM. This will
         usually ensure that each application has a unique PSP
         (loading address). Some networks use the PSP to identify a
         process to make sure that two processes do not try to modify
         a file at the same time. On such networks, running with this
         setting disabled may result in corrupted files. However,
         enabling this setting will take memory away from each
         application.

         should use to determine whether data structures within DOS
         need to be local. There are two other methods to do this:
         internal tables within the device, and an INT 2fh call
         documented in the OEM Adaptation Kit. Both methods are
         preferred to using this setting; it is provided only for
         compatibility with Windows/386 Version 2.x.

         from hard disk controller, bypassing the ROM routine that
         handles these interrupts. Some hard drives might require that
         this setting be disabled in order for interrupts to be
         processed correctly. If this setting is disabled, the ROM
         routine handles the interrupts, which slows the system's
         performance.

         the display for a windowed non-Windows application.