CONFIG.SYS

DEVICEDOSDEVICEHIGHSWITCHARACCDATEBUFFERSHIGHCLS (CONFIG.SYS directive)COUNTRY directiveFCBSHIGHFILESHIGH
CONFIG.SYS is the primary configuration file for the DOS and OS/2 operating systems.wikipedia
110 Related Articles

IBMBIO.COM

DOS BIOSDOS-BIOSDRBIOS.SYS
It is a special ASCII text file that contains user-accessible setup or configuration directives evaluated by the operating system's DOS BIOS (typically residing in IBMBIO.COM or IO.SYS) during boot.
It also loads the DOS kernel (IBMDOS.COM) and optional pre-loadable system components (like for disk compression or security), displays boot menus, processes configuration files (like CONFIG.SYS) and launches the shell (like COMMAND.COM).

Terminate and stay resident program

TSRTerminate and Stay Residentmemory resident
In fact, these will either define some tunable parameters often resulting in reservation of memory, or load files, mostly device drivers and TSRs, into memory.
Parts of DOS itself, especially in DOS versions 5.0 and later, use this same technique to perform useful functions, such as the DOSKEY command-line editor and various other installable utilities which are installed by running them at the command line (manually, from AUTOEXEC.BAT or through from within CONFIG.SYS) rather than loading them as device drivers through statements in CONFIG.SYS.

DR-DOS

DR DOSDR DOS 6.0DR-DOS 7.02
Under DR DOS 3.31, PalmDOS 1.0, Novell DOS 7, OpenDOS 7.01, and DR-DOS 7.02 and higher, a file named DCONFIG.SYS (with "D" derived from "DR DOS"), if present, will take precedence over CONFIG.SYS.
DR DOS offered some extended command line tools with command line help, verbose error messages, sophisticated command line history and editing (HISTORY directive) as well as support for file and directory passwords built right into the kernel.

AUTOEXEC.BAT

The command shell in turn is responsible for processing the AUTOEXEC.BAT file.
When installing Caldera DR-DOS 7.02 and higher, the Windows version retains the name, while the file used by the DR-DOS is named, referred to by the startup parameter in the SHELL directive.

FlexOS

4680 OSFlexOS 286IBM 4680 OS
Under FlexOS, CONFIG.SYS is a binary file defining the resource managers and device drivers loaded.
During boot, the FLEX286.SYS kernel would load the resource managers and device drivers specified in the CONFIG.SYS binary file (not to be mixed up with the similarly named CONFIG.SYS configuration file under DOS), and its shell (COMMAND.286) would execute a CONFIG.BAT startup batch job instead of the common AUTOEXEC.BAT.

Multiuser DOS

Concurrent DOSREAL/32Concurrent DOS 386
While older versions of Concurrent DOS 3.2 to 4.1 did not support CONFIG.SYS files at all, later versions of Concurrent DOS 386 and Concurrent DOS XM, as well as Multiuser DOS, System Manager and REAL/32 will probe for CCONFIG.SYS (with "C" derived from "Concurrent") instead of CONFIG.SYS.
Driver installation was more complex than the simple PC DOS method of copying the files onto the boot disk and modifying CONFIG.SYS appropriately – it was necessary to relink the Multiuser DOS kernel (known as a nucleus) using the SYSGEN command.

Windows 95

95Microsoft Windows 95Windows 95 OSR2
Both CONFIG.SYS and AUTOEXEC.BAT can be found included in the root folder of Windows 95, and Windows 98 boot drives, as they are based on DOS.
In addition, CONFIG.SYS and AUTOEXEC.BAT settings (aside from HIMEM.SYS) have no effect on Windows programs.

COMMAND.COM

COMMANDDOS promptMS-DOS Prompt
After processing the CONFIG.SYS file, DOS proceeds to load and execute the command shell specified in the SHELL line of CONFIG.SYS, or COMMAND.COM if there is no such line.

Installable File System

IFSIFSHLP.SYSIFSHLP
Only the IFS and the filesystem code itself is required and it is loaded via an "IFS=" statement in the CONFIG.SYS file.

File Control Block

FCBDTAFCBs
Such memory reservation is done using the FILES= directive in the CONFIG.SYS file.

DOS

COM1AUX:LPT1
CONFIG.SYS is the primary configuration file for the DOS and OS/2 operating systems.

Scroll Lock

Copy Cursor (FreeKEYB)Copy Cursor (K3PLUS)
DR-DOS 7.02 and higher provides a CONFIG.SYS directive named to change the Scroll Lock status on the fly.

Command-line interface

command linecommand-linecommand line interface
After processing the CONFIG.SYS file, DOS proceeds to load and execute the command shell specified in the SHELL line of CONFIG.SYS, or COMMAND.COM if there is no such line.
In some of these systems (MS-DOS/PC DOS 2.xx, DOS Plus 2.1, DR-DOS 7.02 and higher, PTS-DOS, Embedded DOS, FreeDOS and RxDOS), the setting can also be pre-configured by a SWITCHAR directive in CONFIG.SYS.

A20 line

A20 gateA20 handlerA20
That functionality was enabled by the or directives in the CONFIG.SYS configuration file.

Environment variable

environmentSETpseudo-environment variable
; : This variable is automatically set to the first parameter given to the CONFIG.SYS directive NEWFILE.

List of DOS commands

KEYBPAUSENLSFUNC
Starting with version 6, MS-DOS included the external program MemMaker which was used to free system memory (especially Conventional memory) by automatically reconfiguring the AUTOEXEC.BAT and CONFIG.SYS files.

Configuration file

configuration filesconfig fileconfiguration
CONFIG.SYS is the primary configuration file for the DOS and OS/2 operating systems.

OS/2

OS/2 WarpIBM OS/2OS/2 Warp 4
CONFIG.SYS is the primary configuration file for the DOS and OS/2 operating systems.

Operating system

operating systemsOScomputer operating system
CONFIG.SYS is the primary configuration file for the DOS and OS/2 operating systems.

ASCII

US-ASCIIAmerican Standard Code for Information InterchangeASCII code
It is a special ASCII text file that contains user-accessible setup or configuration directives evaluated by the operating system's DOS BIOS (typically residing in IBMBIO.COM or IO.SYS) during boot.