MS-DOS v6.22 Help: EMM386

------------------------ MS-DOS v6.22 Help: EMM386 -------------------------
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                                   EMM386

Enables or disables EMM386 expanded-memory support on a computer with an
80386 or higher processor. The EMM386 command also enables or disables
Weitek coprocessor support. Do not use this command when Windows is
running.

The EMM386 device driver, EMM386.EXE, provides expanded-memory support and
also provides access to the upper memory area. For information about
EMM386.EXE, see <EMM386.EXE>.

Syntax

    EMM386 [ON|OFF|AUTO] [W=ON|W=OFF]

To display the current status of EMM386 expanded-memory support, use the
following syntax:

    EMM386

Parameters

ON|OFF|AUTO
    Activates the EMM386 device driver (if set to ON), or suspends the
    EMM386 device driver (if set to OFF), or places the EMM386 device driver
    in auto mode (if set to AUTO). Auto mode enables expanded-memory support
    only when a program calls for it. The default value is ON.

W=ON|W=OFF
    Enables (if set to W=ON) or disables (if set to W=OFF) Weitek
    coprocessor support. The default value is W=OFF.

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                               EMM386--Notes

Installing the EMM386.EXE device driver

To use the EMM386 command, you must have an 80386 or higher processor, and
you must also install the EMM386.EXE device driver by using the DEVICE
command in your CONFIG.SYS file. If you try to use the EMM386 command on a
computer that does not have an 80386 or higher processor, MS-DOS displays
the following message:

    EMM386 driver not installed

Reactivating EMM386 expanded-memory support

If EMM386 was loaded when MS-DOS started but is not currently in use, the ON
parameter reactivates expanded-memory support.

Suspending EMM386 expanded-memory support

If EMM386 expanded-memory support is currently active, handle 0 is the only
handle allocated, and EMM386 is not providing access to the upper memory
area. The OFF parameter suspends EMM386 expanded-memory support. When EMM386
expanded-memory support is off, the EMM386.EXE device-driver header is
changed so that programs cannot use expanded memory. This enables you to run
non-VCPI-compliant programs such as Windows 3.0 in Standard mode.

Enabling and disabling Weitek coprocessor support

If the W=ON parameter is specified and the OFF parameter (different from the
W=OFF parameter) is not, EMM386 enables Weitek coprocessor support. The high
memory area (HMA) must be available to enable Weitek coprocessor support. If
you load MS-DOS into the HMA by specifying DOS=HIGH, you may not be able to
enable Weitek coprocessor support.

If you specify the W=ON or W=OFF parameter and no Weitek coprocessor is
installed in your computer system, MS-DOS displays the following error
message:

    Weitek Coprocessor not installed

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