Specifies that the operating system should maintain a link to the upper memory area, load part of itself into the high memory area (HMA), or both. You can use this command only in your CONFIG.SYS file.
For information about loading a device driver into
the upper memory area, see the
For information about loading a program into the upper memory area, see the LOADHIGH command.
You must install the HIMEM.SYS device driver or another extended memory manager before you specify either DOS=HIGH or DOS=UMB.
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. If your computer has an 80386 or 80486 processor, you can use EMM386.EXE for your UMB provider.
If you specify DOS=UMB. and no UMB provider is installed, the operating system will not display an error message.
If you specify the HIGH parameter, the operating system attempts to load part of itself into the HMA. Loading part of the operating system into the HMA frees conventional memory for programs. If you specify DOS=HIGH and the operating system is unable to use the HMA, the following message will appear:
HMA not available Loading DOS low
You can include more than one parameter on a single DOS command line, using commas to separate them. The following command lines are valid:
You can place the DOS command anywhere in your CONFIG.SYS file.