The Disk Operating System (DOS) is a collection of programs which manages files on a disk. It doesn't matter whether the disk is a floppy disk, a hard disk, or an optical disc -- they all require DOS to manage and control the files stored on them.
Several different companies make DOS programs. MicroSoft's DOS is called MS-DOS. Digital Research's DOS is called DR-DOS (but was recently purchased by the Novell Corporation and will simply be called Novell DOS in the future). IBM's DOS is called IBM DOS or PC-DOS.
Most of the commands and functions in the different DOS's are similar and compatible with each other. As the competition to improve a company's DOS increases, DOS is becoming more and more powerful (yet it is becoming more and more complex). You will now find utility programs such as an anti-virus program and a disk de-fragmenter included with DOS.
Because DOS is such a complex collection of programs, it is impossible to cover the topic in one reference sheet. Each DOS has accompanying HELP commands and you should refer to these for more information. The rest of this sheet will list some of the most common DOS commands and give a brief description of each.
DOS Commands
attrib -- allows you to change the attributes or characteristics of a file. Using attrib you can hide files or make them 'read only' so they cannot be deleted or changed.
backup (msbackup) -- allows you to backup (archive) files for safe storage. This program allows you to backup only those files that have been changed since your last backup session.
cd -- change directory to a lower or higher directory on the directory tree structure.
chkdsk -- check disk for files that are not linked properly. Reports back the size of the disk, how much space has been used, how much space is marked as defective, and whether or not files are mis-linked.
cls -- clears the screen
copy -- copy a file from one disk or directory to another disk or directory. Copy will also allow you to copy from a device such as the console monitor to a file (thus turning your computer into a mini word processor).
date -- command to change the date on the computer system.
del -- delete. Allows you to delete a file or a series of files.
dir -- directory. Allows you to display files in a directory. This command has several switches you can use to display just files, just directories, just hidden files, etc. The switches also control the display by pausing it, alphabetizing filenames, printing file names across rather than down the screen, etc.
diskcopy -- used to copy an entire disk to another disk of the same size and type.
edit -- an ASCII text editor used to write batch files or to write programs.
format -- initialize a new disk and prepare it to save data.
help -- online help for more information and help on various DOS commands.
label -- used to change the label internally stored on the disk.
md -- make directory. Makes a sub-directory.
mem -- memory checking utility. Allows you to see which programs are in memory, how much memory of different memory types you have, what size the programs are, and which area of memory programs are stored.
path -- command to add subdirectories to the "search path". Subdirectories listed in the path, are searched by DOS when a program or data file is requested. If the subdirectory is in the path, you do not need to change and be in the current directory to run programs in that directory.
prompt -- command used to change the display of the prompt. You can add the path to the prompt by typing $P. You can place a greater-than symbol in the prompt by typing $G. You can print the current system time by typing $T in the prompt. The most common prompt is $P$G.
rd -- remove directory. The directory must be empty before it can be removed. A related command available in some DOS's is deltree.
ren -- rename. Allows you to rename a file.
restore -- restore files that have been backed up.
time -- allows you to view or change the system time.
tree -- displays a tree diagram of all directories and subdirectories on the disk.
type -- displays a text file on the screen. Output can be redirected to a printer or a file by using the redirection symbol (>).
undelete -- undelete or unerase a file.
ver -- displays the version of DOS.
vol -- displays the volume information.
xcopy -- copies multiple files at a time.
The Windows and OS/2 operating systems use a graphical interface so you can do DOS commands with a mouse instead of memorizing and typing the command words.
The DOSSHELL is a menu system which comes with DOS and performs many of the DOS commands with a mouse or an easy-to-use menu system rather than typing the command words at the keyboard.
