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 dos(CMD)                        19 June 1992                        dos(CMD)


 Name

    dos - specify that MS-DOS is to maintain a link to the upper memory area

 Syntax


    dos=high|low[,umb|,noumb]

    dos=[high,|low,]umb|noumb


 Parameters


    umb|noumb     Specifies whether MS-DOS should maintain a link between
                  conventional memory and the upper memory area.  The umb
                  parameter provides this link.  The noumb parameter discon-
                  nects this link.  The default setting is noumb.

    high|low      Specifies whether MS-DOS should attempt to load a part of
                  itself into the HMA.  Use the high parameter to enable
                  MS-DOS to load itself into the HMA.  Use the low parameter
                  to keep all of MS-DOS in conventional memory.  The default
                  setting is low.


 Notes


    Must install HIMEM.SYS for dos=umb or dos=high

    You must install the HIMEM.SYS device driver before you specify either
    dos=umb or dos=high.

    Using the umb parameter

    You must specify the dos=umb command in order to load programs and device
    drivers into the upper memory area.  Using the upper memory area frees
    more space in conventional memory for programs.  In addition to using
    this command, you must install an upper-memory-block (UMB) provider.

    Using the high parameter

    If you specify the high parameter, MS-DOS attempts to load part of itself
    into the HMA.  Loading part of MS-DOS into the HMA frees conventional
    memory for programs.

    Combining parameters

    You can include more than one parameter on a single dos command line,
    using commas to separate them.  For example, the following command lines
    are valid:

       dos=umb,low

       dos=high,umb


    You can place the dos command anywhere in your CONFIG.SYS file.

 Related commands

    For information about loading a device driver into the upper memory area,
    see the devicehigh(CMD) command.

    For information about loading a program into the upper memory area, see
    the loadhigh(CMD) command.