Page 57MS-DOSShort forMicrosoft Disk operating system, MS-DOSis a non-graphical command line operating system derived from 86-DOS that was created for IBM compatible computers. MS-DOS originally written byTim Paterson and introduced byMicrosoftin August1981 and was last updated in1994when MS-DOS 6.22 was released. Today, MS-DOS is no longer used; however, the command shell, more commonly known as theWindows command lineis still used by many users. In the picture aside, is an example of what a MS-DOS window more appropriately referred to as the Windows command line looks like under MicrosoftWindows.The command interpreter is integrated in the file command.com with the internal commands for MS-DOS. Together with the file io.sys for simple device routines like the access to the monitor, keyboard, fixed storage disks and interfaces as well as the booting code these form the base operating system. DOS works very hardware near.

FIELD OF APPLICATION- Booting system for storage media- File management- For single user systems only- Network client (NetBEUI, IPX/SPX, TCP/IP)- Batch processing

STRUCTURE INFORMATION- 16-bit Single tasking operating system, (formerly 8-bit)- Command interpreter for internal and external commands- External driver software imbedding for periphery devices possible

SYSTEM ENVIRONMENT- Minimum: 512 kb RAM, 5 mb hard disk storage (depends on version for full installation)- FAT file system- Executable with every x86 compatible CPU- Low RAM and fixed storage disk needs

VERSIONDATE

VERSION

1981 Aug.MS-DOS 1.0, formerly QDOS/86-DOS, can use at maximum 128 kb RAM, FAT established

1982 Aug.MS-DOS 1.25, support for double-density floppy disks

1983 MarchMS-DOS 2.0, support for IBM 10 mb hard disk, directory and DD 5.25" floppy disk drives with up to 360 kb

1983 Dec.MS-DOS 2.11, extended character sets

1984 Aug.MS-DOS 3.0, support for high density floppy disk drives with 1.2 mb and hard disk devices with 32 mb capacity

1984MS-DOS 3.1, first time with network support

1987 AprilMS-DOS 3.3, extended for IBM's PS/2 computer, supports now bigger 3.5" hard disk Drives and floppy disk drives, multiple partitions, character sets for different languages

1988 JulyMS-DOS 4.0, XMS support, partitions with up to 2 gbyte, graphical shell, bug fixes

1988 Nov.MS-DOS 4.01, supports multiple partitions bigger than 32 mb, bug fixes

1991 JuneMS-DOS 5.0, Major Release

1992MS-DOS 5.0a, bug fixes for Undelete and Chkdsk

1993 Aug.MS-DOS 6.0, Competition to Novell's DR-DOS 6, DoubleSpace, Anti-Virus program, Defrag, Move command, improved MSBACKUP and several boot configurations, memory optimizer MEMMAKER, DOS Shell is delivered separately on floppy disks

1993 Nov.MS-DOS 6.2, DoubleSpace becomes incompatible to the previous version, Scandisk, improved of DISKCOPY and SmartDrive

1994 MarchMS-DOS 6.21, because of law conflict with Stac Electronics Double Space is removed from MS DOS

1994 MayMS-DOS 6.22, Microsoft licenses double disk of VertiSoft Systems and designates it in DriveSpace, last official standalone version

1995 Aug.MS-DOS 7.0, MS-DOS component for Windows 95, LFS support through VFAT, more DOS programs are delivered on the Setup CD-ROM in the "oldmsdos" directory

1996 Aug.MS-DOS 7.10, MS-DOS component for Windows 95 B and higher, supports the first time FAT 32 hard disks

2000MS-DOS 8.0, MS-DOS component for Windows ME, last MS-DOS version

INTERNAL & EXTERNAL COMMANDSInternal commands are commands that are a part of the MS-DOS command interpreter. They are small routines and are stored within the COMMAND.COM file. External commands are not a part of COMMAND.COM. They are stored on a separate disk. COMMAND.COM contains a table which has the names of all the internal commands stored in it. After accepting a command, it searches that table for the command just entered. If found, the command is an internal command and its code from the COMMAND.COM file will be executed. If the name of the command just entered is not present in the table, the command is an external command. Hence, it searches for the command on the disk and upon finding it; the command interpreter loads it into the memory and executes it. Otherwise a message "Bad command or file name" is displayed.

INTERNAL COMMANDSAll the file names used in internal commands can be preceded by a drive name and a path which are indicated by the following terms.d: - drive, sd: - source drive, td: - target drive, cd : - current directory Clearing the screen- CLSThis command erases all the characters on the screen and takes the cursor control to the first row of the screen.Syntax: CLS

Entering the current date- DATEDATE allows you to reset the system date to the current date or obtain the current date from the system clock. In all the following commands, the parameters enclosed in square brackets are optional.Syntax: DATE (mm-dd -yy) or DATE (mm/dd/yy) or DATE [mm . dd . yy]

Entering the current time- TIMEDisplays the current time and allows you to reset the time.Syntax: Time [ hh : mm[ : ss [ xx ] ] ]

Listing files in a directory- DIRDIR is used to display the contents of a directory, ie, the file names, the file size in bytes, the date and time of last modification, the number of bytes available on the disk, and any subdirectories under the current directory. The file name under DOS is represented by a primary name and a secondary name. The primary name can be up to 8 characters of length; it is followed by a dot and a secondary name or extension. The secondary name can be up to 3 characters of length. The file name can be made up of alphabets, digits. underscores and hyphens. No other characters are allowed.Syntax: DIR [d:] [path] [filename] [/P] [/W] [/S]

Optionsd:path filename-SPECIFY] the drive letter, path name, or file name when you wishto obtain a directory listing of files that are not in the current directory./P- Tells DOS to pause when the screen has been filled. To see the next screen of filenames you have to press any key./W- Displays a directory showing only file name in a wide format-five names across each line./S- Displays the files from the subdirectories also.

Displaying the contents of a file-TypeTYPE displays a file's content on the screen. This command continuously scrolls the file on the screen. To freeze the text use pause key. To stop the TYPE command press Ctrl-C. The contents of binary files and Exe files will be meaningless. Only files which are in ASCII format can be typed.Syntax: Type [ d: ] [path] filename

Copying files- COPYCOPY is used to copy files with the same or different names.Syntax: COPY [ /A] [/B] [sd:] [spath] sfilename [td : ] [tpath][tfilename]Options/A or /B indicates whether the preceding file and all subsequent files are to be read as ASCll (text) or binary files, and it is in effect until further modified.sd: spath sfilename- Specifies source file or files to be copied.td: tpath tfilename- Specifies target file or files to be copied to. The filename can bespecified if you wish to rename the target file during copy. If not specified, the source file name itself will be given to the target file also. But in this case the target drive or directory must be specified. This is because we cannot store two files under same name in the same directory.

Deleting files- DELThis command is used to delete any or groups of files from the directory.Syntax: DEL [d:] [path] filename

Renaming files-Rename {REN)This command will change the name of the given file, with the new name given by you. REN will not allow two files to have the same name at the same time. Never rename special files that application programs require to operate.Syntax: REN[d:] [path] oldfilename newfilename

Old file name- Specifies the file, to change its name.New fi1e narne- Specifies the new name to be assigned to the file {must be on the same drive and path as the file to be renamed).

Creating new subdirectories- Mkdir (MD)This command creates a new subdirectory.Syn-: MD[d:]pathd: -Specifies the drive in which you wish to create the new subdirectory.Path - Specifies path of directory names, including the name of the sub-directory to be created. The entire path name must not exceed 63 characters, including the backslashes. Removing directories- RMDIR ( RD)Only empty directories may be removed. First you have to remove all the files in the directory using DEL or Erase command. You cannot delete the root directory.Syntax: RMDIR [d:] path or RD [d:] path

Changing the system prompt- PromptAllows you to change the system prompt.Syntax: PROMPT [prompt]OptionsThe prompt can be any literal message displayed on the screen, and it can include any one of the following special characters.$t Current time$d Current date$n Default drive$p Current path$v DOS version number$g Greater-than character (>)$l Less - than character (