Type: Internal (5.0 and later)



Purpose: Used in the CONFIG.SYS file to specify the memory location for DOS. It is used to load DOS into the upper memory area and to specify whether or not the upper memory blocks will be used.


Whenever you use the DOS command in your CONFIG.SYS file, you must provide at least one option with it. If you want to include more than one option, you separate them with commas. You must load an extended memory manager such as HIMEM.SYS in your CONFIG.SYS file before you can use the DOS=high command option.

high|low Tells DOS whether to load itself into high memory (high) or conventional memory (low). Before DOS can be loaded into high memory, an extended memory manager (such as HIMEM.SYS) must be loaded. The default is low.

umb|noumb Tells DOS whether or not it should manage upper memory blocks (umb) created by an UMB provider such as EMM386.EXE. The default is noumb (no umb).


To load the extended memory manager, HIMEM.SYS, and then tell DOS to load itself into high memory and to use upper memory blocks for memory resident programs, enter the following lines into your CONFIG.SYS file:

device=c:\dos\himem.sys dos=high, umb

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