devicehigh MS-DOS Command

Type: Internal (5.0 and later)

Syntax:

DEVICEHIGH=[d:][\path]\filename [parameters] DEVICE [/L:region, min;region,min…] [/S] =[d:][\path]\filename DEVICE [size=hexsize] [d:][\path]\filename [parameters]

Purpose: Used in the CONFIG.SYS file to load device drivers into upper memory.

Discussion

Before DOS can load a device driver into upper memory, there must be an upper memory block (UMB) provider (such as EMM386) available and there must be enough space in that UMB. If there is not enough space in the UMB, the device driver will be loaded into conventional memory. You can check to see which device drivers have been loaded into high memory by using the /MEM /C command. DOS executes device drivers in the order in which they appear in the CONFIG.SYS file. For some device drivers the order of execution is important. If you load a device driver into high memory and then find that your system will not boot, you can press the F5 key to bypass the CONFIG.SYS file or you can press F8 to choose, interactively, the CONFIG.SYS lines you want to execute. (This feature is available only with DOS Version 6. If you are using an earlier version of DOS, you can use a bootable disk from the floppy drive to bypass the problem CONFIG.SYS file.) The following is a list of the device drivers provided with MS-DOS that can be loaded into high memory: ANSI.SYS EGA.SYS DBLSPACE.SYS PRINTER.SYS DISPLAY.SYS RAMDRIVE.SYS DRIVER.SYS SETVER.EXE

Options

parameters Used to specify any parameters required by the device driver. They are passed by DOS to the driver when it is loaded into memory. /L:region, min – Available with DOS Version 6, this option specifies the region in upper memory and the minimal size in bytes which the device driver should occupy. More than one region can be specified if you separate each region with a semicolon. This option must precede the filename of the device driver. /S – Available with DOS Version 6, tells DOS to shrink the UMB to the size specified by the /L option and create a new UMB from the remainder. This option must precede the filename of the device driver. size=hexsize – Available with DOS Version 5 and later, this option specifies the minimum size memory block into which DOS should attempt to load the driver. This option must precede the filename of the device driver.

Example

To use the file ANSI.SYS as the standard device driver and to load it into the upper memory area, enter the following line in your CONFIG.SYS file: devicehigh=c:\dos\ansi.sys