| DOS |
|
| Specifies that MS-DOS 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. |
|
| Syntax |
|
| DOS=HIGH|LOW[,UMB|,NOUMB] |
|
| DOS=[HIGH,|LOW,]UMB|NOUMB |
|
| Parameters |
|
| UMB|NOUMB |
| Specifies whether MS-DOS should manage upper memory blocks (UMBs) |
| created by a UMB provider such as EMM386.EXE. The UMB parameter |
| specifies that MS-DOS should manage UMBs, if they exist. The NOUMB |
| parameter specifies that MS-DOS should not manage UMBs. The default |
| setting is NOUMB. |
|
| HIGH|LOW |
| Specifies whether MS-DOS should attempt to load a part of itself into |
| the HMA (HIGH) or keep all of MS-DOS in conventional memory (LOW). The |
| default setting is LOW. |
|
| Related Commands |
|
| For information about loading a device driver into the upper memory area, |
| see the DEVICEHIGH command. |
|
| For information about loading a program into the upper memory area, see the |
| LOADHIGH command. |
|
|
| DOSes |
|
| Must install HIMEM.SYS for DOS=UMB or DOS=HIGH |
|
| You must install the HIMEM.SYS device driver or another extended memory |
| manager 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. 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, MS-DOS will not |
| display an error message. |
|
| 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. If you specify DOS=HIGH and MS-DOS is unable to use the HMA, |
| the following message will appear: |
|
| HMA not available |
| Loading DOS low |
|
| 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. |
|
|
