Introduction to DOS C:\>

1. Introduction to DOSC:\>

2. Operating Systems • Software programs that • control thousands of operations • provide an interface between the user and the computer • run applications. • An OS is designed to control the operations of programs such as Web browsers, word processors, and e-mail programs. • Computers that are capable of handling concurrent users and multiple jobs are often called "network servers" or simply "servers." Servers have operating systems installed called Network Operating Systems (NOS).

3. Operating Systems • There are three basic elements that make up the major design components of any operating system. These components are: • User interface – A user interacts with the computer's OS through the user interface. Simply put, the user interface is the part of the operating system that a person can use to issue commands • Kernel – This is the core of the OS. The kernel is responsible for loading and running programs (processes) and for managing input and output. • File management system – The file management system is what the OS uses to organize and manage files.Most operating systems use a hierarchical file system in which files are organized into directories under a tree structure. The beginning of the directory system is referred to as the root directory.

4. Operating Systems Functions • Regardless of the size or complexity of the computer or its operating system, all operating systems perform the same basic functions: • File and folder management • Management of applications • Support for built-in utility programs • Access control to computer's hardware

5. Operating Systems Functions What type of software has access to the BIOS?

6. Disk Operating Systems • Microsoft developed the Disk Operating System (DOS), also called MS-DOS, in 1981. • DOS was designed then for the IBM Personal Computer. • Windows 98 and Windows 2000 both support DOS commands in order to address compatibility issues related with older applications. • Simply put, DOS is a collection of programs and commands used to control the overall computer operation in a disk-based system.

7. Disk Operating Systems • When running Windows 98, go to Start > Run and type command. • In Windows 2K or XP, type cmd. • Exit returns you to Windows.

8. Basic Elements of DOS • The following are some of the basic things to remember when working with DOS. • DOS is a command line operating system; it is not user-friendly. The best way to learn DOS is to use it. • DOS can only run one program at a time. It is not multitasking. • DOS can only run small programs and has memory limitations. • DOS is an essential tool for IT professionals and is used extensively for troubleshooting.

9. DOS File Structure • Programs and data are stored the same way a document would be filed in a folder in a file cabinet. • In DOS, they are called files and are grouped together in directories\subdirectories. • Directories are much like the folders in the file cabinet. • Directories can be nested inside other directories, just like a folder placed inside another folder. Nested directories are referred to as subdirectories. • Directories became known as folders in the Windows OS.

10. DOS Files • A file is simply a block of logically related data, given a single name, and treated as a single unit, such as programs, documents, drawings and other illustrations, sound files, and so on. Files are referred to by filenames. • In DOS, filenames can be up to 8 characters with an extension of 3 characters. (8 + 3) • The extension is separated from the main portion of the filename by a period and it identifies what type of file it is. • Example: mynotes.txt

11. DOS File Attributes • In DOS, all files have attributes, which are a set of parameters that describe a file. The common attributes for DOS files include: • Hidden File – The user will not see this type of file with any kind of normal file search in a DOS environment. • Read Only – The user can open and read this type of file but cannot write or modify the file in any way. • Archive (backup) status • System File – A file needed by the DOS operating system for a successful bootup.

12. DOS Directory Structure • Hard drives organize the disk into directories and subdirectories. • The main directory is known as the root directory. • All other directories, if they exist, then radiate (branch out) from the root directory, similar to the branches of a tree. • Locating any given file requires knowledge of three things: the drive, directory and subdirectory in which the file is found. • Example: C:\Directory\Subdirectory\Filename

13. DOS Directory Structure • In MS-DOS, the format for specifying the path to a file is as follows: • C:\directory name\subdirectory name\filename • The “C:” represents which disk we are looking at. A floppy disk might look like this “A:\” instead of “C:\” (which is usually a hard drive). • The first back slash indicates the root directory, which is present on all DOS disks. • The back slash (\) after each item signifies the presence of a directory or subdirectory.

14. Basic DOS Commands • In DOS, the main user interface is the command line. • The command line is the space immediately following the DOS prompt, C:\> where C:\ represents the hard disk drive root directory, and '>' is known as the prompt. • All the DOS commands are typed to the right of the prompt and executed by pressing the return (ENTER) key on the keyboard.

15. Basic DOS Commands

16. Executing DOS Commands • To execute a command, you simply type it in at the prompt and hit [Enter] • The “ver” command prints the current version of DOS you are running. To execute the command simply type: ver [Enter] • DOS is not case sensitive. Ver is the same as ver.

17. Getting Help with Commands • Use the help command to display a list of DOS commands and a brief description of each. • For more specific details type help followed by the command. * For example to see how to use the DIR command type: help dir

18. Most Commands Have Parameters • In order to use most commands, you have to give it some information. • Everything that follows the name of a command is called a parameter. • The following command has one parameter: • mkdir mydirect • mk mydirect

19. Most Commands Have Parameter Switches • A parameter switch is a parameter that generally starts with a forward slash “/”; • These switches configure the command to do special tasks. • The dir command has numerous switches such as /p to PAUSE a long listing or /w to display in WIDE format.

20. The /? Parameter Switch • Almost all DOS commands have the /? parameter switch that displays the help screen. • Typing the command /? is the same as typing help the command • For example, dir /? is the same as help dir

21. How to Read A Help Screen DEL [/P] [/F] [/S] [/Q] [/A[[:]attributes]] names names Specifies a list of one or more files or directories. Wildcards may be used to delete multiple files. If a directory is specified, all files within the directory will be deleted. /P Prompts for confirmation before deleting each file. /F Force deleting of read-only files. /S Delete specified files from all subdirectories. /Q Quiet mode, do not ask if ok to delete on global wildcard /A Selects files to delete based on attributes attributes R Read-only files S System files H Hidden files A Files ready for archiving - Prefix meaning not

22. []Brackets Represent Optional Parameters • In the previous example they show the order (often not important) and choices of parameters. • DEL [/P] [/F] [/S] [/Q] [/A[[:]attributes]] names • Anything in square brackets is optional. • The rest of the listing describes what each parameter does. • Sometimes a colon is attached to a switch if you can be more specific in what you want. • The command DEL /A:H *.* will erase all file with the HIDDEN attribute.

23. More on Directories • If you were to run DIR to show you all the files in the current directory then you would see 2 special files . AND .. • The single dot represents the current directory and the double dot represents the parent directory.

24. Parent & Child Directories • The root directory is the HIGHEST parent: C:\ • C:\Info would be a child of the root directory. • C:\Info\Module1 would be a child of the Info directory. • What happens if I type dir . ? • What if I type dir .. ?

25. Running Applications • It’s easy to run an application. Simply find the executable for it and type in the command. • Lets try it: • cd \window\system32 • Sol • Or use the Start command: • Start c:\

26. Path • You can run some programs without being in the current directory of that program. • That is what the PATH is for. It searches all the directories listed in the PATH when looking for a program. • For example, if in the root directory you type: notepad then windows runs it because the c:\window folder is in the path.

27. Exiting a DOS Shell • To quit a DOS shell: • Type: Exit • If the DOS shell is in a window click the X in the upper right hand corner. Hint: You can toggle a full screen DOS shell by hitting ALT-ENTER.

28. What Have You Learned? • What is a DOS shell? • What is a folder called in DOS? • What is the root directory? • How do you change to disk drives? • How do you move to a subdirectory? • How do you move back to a parent directory?