Using the command line interface - PC Based Instrumentation and Control - page 134

Using configuration
files and device drivers

DOS provides a number of device drivers and utility programs which, in an ear-

lier DOS/Windows environment could be installed from CONFIG.SYS. Typical
of these drivers were:

Function Device driver (generic name)

Disk caches IBMCACHE.SYS, SMARTDRV.SYS

RAM drives RAMDRIVE.SYS, VDISK.SYS

Additional disk drives DRIVER.SYS

Memory management XMAEM.SYS, EMM386.SYS, EMM386.EXE

Display adapter DISPLAY.SYS

configuration
Printer configuration PRINTER.SYS

In a modern Windows NT or XP environment CONFIG.SYS is replaced
by CONFIG.NT. Unless a different start-up file is specified in an application's
Program Interchange File (PIF), CONFIG.NT is used to initialize the MS-DOS
environment.
By default, no information is displayed when the DOS environment is initial-
ized. If required you can display CONFIG.NT/AUTOEXEC.NT information by
simply adding the command echoconfig to the CONFIG.NT (or other start-up
file). When you return to the command prompt from a TSR or while running
a DOS-based application, Windows runs COMMAND.COM. This allows the
TSR to remain active. To run CMD.EXE, the Windows command prompt,
rather than COMMAND.COM, simply add the command ntcmdprompt to
CONFIG.NT (or other start-up file).
Also by default, it is possible to start any type of application when running
COMMAND.COM. However, if an application other than an MS-DOS-based
application is started, any TSR that is running may be disrupted. To ensure that
only MS-DOS-based applications can be started, you can add the command
dosonly to CONFIG.NT (or other start-up file).
As an example of the use of a DOS driver, the expanded memory manager
(EMM) is configured by means of the following command syntax:

EMM = [A=AltRegSets] [B=BaseSegment] [RAM]

Where: AltRegSets specifies the total Alternative Mapping Register Sets
you want the system to support (in the range 1-255). The default
value of AltRegSets is 8.
BaseSegment specifies the starting segment address in the DOS
conventional memory you want the system to allocate for EMM page
frames. The value must be given in hexadecimal in the range 0 1000
to 0 4000. Note that the value of BaseSegment is rounded down
to a 16 KB boundary and the default value is 0 4000.
RAM specifies that the system should only allocate 64 KB address
space from the upper memory block (UMB) area for EMM page
frames and leave the rest (if available) to be used by DOS to support
the loadhigh and devicehigh commands. By default, the system
will allocate all possible and available upper memory block (UMB)
for page frames.