Used to load device drivers into conventional and upper memory respectively.
Syntax:To load a device driver into conventional memory:
To load a device driver into upper memory:
Notes:Before using DEVICEHIGH to load device drivers into the upper memory area, Himem.sys and a UMB provider, such as Emm386.sys, must be loaded in conventional memory (using DEVICE=himem.sys and DEVICE=emm386.exe commands). The DOS=umb command must also be included in Config.sys.
If DEVICEHIGH is used but there is insufficient upper memory area available to load the specified device driver (or if the DOS=umb command is missing), the driver will be loaded into conventional memory instead.
By default, if a region is specified, DEVICEHIGH will load a driver into the largest UMB in that region so long as that UMB is larger than the driver's load size (usually equal to the size of the file).
Some drivers require extra memory when running and it is for these that minsize can be used to ensure that the driver will not be loaded into a UMB that is too small for it. If minsize is specified, the driver is loaded into that region only if it contains a UMB that is larger than both the driver's load size and the minsize value.
If a device drivers requires the use of more than one area of memory, these can be specified by separating the block numbers with a semicolon.
To determine how a particular device driver uses memory, and to list the free areas of memory, see the MEM command.
Examples:To load the device driver Ctmmsys.sys into region 2 of upper memory, and noting that it requires 10416 bytes to run although its file size is only 10350 bytes:
DEVICEHIGH /L:2,10416 =c:\sb16\drv\ctmmsys.sys
To load the driver Pts.sys in blocks 2 and 3: