DOS Operating systems

1. Basic MS-DOS

2. • Tim Paterson
- Original author of MS-DOS
- graduated from U of Washington in 1978
- worked as an engineer in Seattle Computer Products
- designed an 8086 CPU card for S-100 Bus in May 1979
- began designing DOS in 1980 after IBM had released
their new 8086 microprocessor (16-bit)
• objectives in design of DOS
- as simple as possible
- make it fast and efficient
- written in 8086 assembly language

3. • In college, Paterson wrote a multi-
tasking operating system for the Z80
microprocessor as a term project.
Therefore, Paterson had confidence in
writing an OS for 8086 computer.
Patterson spent half of his time working
on Qdos from April to July, 1980. QDOS
was completed in July, 1980.

4. History
• MS-DOS 1.0 was released in August 1981, and
was updated until April 1994 when it was
replaced by Windows 95
• All versions of windows still contain some
type of DOS, in windows 95 and 98 you can go
to run and type command to get to DOS
prompt, in NT, 2000, and XP you can type CMD
and get DOS.

5. DEVELOPMENT HISTORY
Date Version Release
August 12,
1981
DOS 1.0 – IBM’s release
Used Patterson’s 86-DOS
May 1982 DOS 1.1
IBM’s release of DOS to handle new
double-sided drives
August 1982 DOS 1.25 Microsoft’s own release of
DOS 1.1
March 1983 DOS 2.0 for IBM’s PC-XT
Support 10MB hard drives, 3-internal
expansion slots, hierarchical tree
structure

6. DEVELOPMENTS cont.
Date Version Release
March 1984 DOS 2.1 IBM’s release
Handled hardware errors called PCjr
1984 DOS 2.11 Microsoft’s release
Added international time, date, currency, and
keyboard support.
1984 DOS 3.0 for IBM’s 16-bit PC-AT system
Support 1.2MB diskettes and hard drives
over 10MB. Designed by Microsoft to
support IBM network hardware
November 1984 DOS 3.1
Provided better aliasing – made DOS treat
directories as drives. Handled network
hardware

7. DEVELOPMENTS cont.
Date Version Release
January
1986
DOS 3.2
Introduced and provided support of 3-
1/2 floppies and 720K disk
April 1987 DOS 3.3 IBM’s release
FDISK can be used to create 32MB or
smaller logical drives from extended
partitions
1987 DOS 3.30 Compaq’s release
Support 1.44MB diskettes and
multiple 32MB disk partitions
November
1987
DOS 3.31 Compaq’s release
Support drives greater than 32MB

8. Date Version Release
July
1988
DOS 4.0 IBM’s release
Added a DOS Shell interface and support for disk
partitions greater than 32MB. Provided support for
mouse and graphical interfaces.
Novem
ber
1988
DOS 4.01- Fixed bugs introduced in 4.0
June
1991
MS-DOS 5.0 Microsoft’s release
Allowed DOS to reside in area above 640K memory.
Provided support for loading device drivers. Provided
an improved DOS Shell
March
1993
DOS 6.0 Microsoft’s release
Introduced DoubleSpace disk compression
DEVELOPMENTS cont.

9. DEVELOPMENTS cont.
Date Version Release
November
1993
DOS 6.2 Microsoft’s release
February
1994
DOS 6.21 Microsoft’s release
Removed DoubleSpace disk
compression
June 1994 DOS 6.22 Microsoft’s release
Introduced “DriveSpace” disk
compression
April 1995 DOS 7.0 IBM’s release
August 1995 DOS 7.0 Microsoft's release

10. Basic Structure
• Most DOS commands use the same structure
• Command Source Destination /Switch
• The switch will give options to the command
• Example COPY A:file.txt c: /v
• /v will verify if the file copied correctly

11. MS-DOS Prompt
• The prompt in MS-DOS displays your
current directory
• C:doscommands> means you are in that
directory, and any command you use will
apply to the current directory unless you
specify a different one.

12. DOS Naming
• The file name cannot be longer then 8
characters, and extensions cannot be
longer then 3 characters.
• Characters like * + = | [ ] : ; “ < > , ? /
cannot be used in DOS names.

13. Wildcard characters
• Wildcard character will replace a single
letter, or word with a wild character
• * will replace any amput of characters, and
? Will replace one.
• Example: copy a:/*.txt c:/ will copy all text
files to drive c:/
• Example 2: copy a:/?????.txt c:/ will copy
any 5 letter text file to c:/

14. Basic Commands CD
• CD- Change directory
• You use this command when you want to
change the directory.
• Example: CD C:DOS will bring you to the
dos folder

15. Basic Commands CD..
• CD.. - brings you to the previous directory.
• Example: if you are in C:DOSFOLDER
CD.. Will bring you to C:DOS

16. Basic Commands COPY
• COPY will copy the file from one location
to another
• Example COPY A:file.txt c: will copy the
file from a: to c:

17. Basic Command XCOPY
• XCOPY can move files, directories, and
whole drives from one location to another,
It is more powerful then the copy
command, and has a lot of switches.

18. Basic Commands DIR
• DIR will display the contents of the folder

19. Basic Command DEL
• DEL will delete a file or an empty directory
from the drive

20. Basic Command EDIT
• EDIT will open a text file

21. Basic Commands MOVE
• MOVE will move the file or directory from
one location to another
• Example: MOVE a:file.txt c:file.txt will
move the file to the c: drive

22. Basic Commands REN
• REN will rename the file
• Example : REN file.txt myfile.txt will
rename the file.txt to myfile.txt

23. Basic Commands MD
• MD is used to make a directory (folder) in
MS-DOS.
• Example: MD myfolder will make a folder
called myfolder in current directory

24. Basic Commands DELTREE
• DELTREE command will delete the folder
and all of its contents, including other
folders.
• Example: DELTREE C:myfolder will
delete the folder and all the contents.

25. Basic Command TREE
• TREE shows you all of the folders and
files in current directory like explorer in
windows.

26. Basic Commands CLS
• CLS Will clear the contents of the screen

27. Attributes
• Attributes are the properties of a file such
as hidden, read-only, archive or system
file.
• In MS-DOS you can view/change
attributes with the attrib command.
• Example: attrib +r file.txt will make the file
read-only.

28. The Help Switch /?
• You can use the help switch with any
command. It will give you the command
structure, and the availible switches.

29. DOS Internal Structure
• The structure of Disk Operating System for
IBM PC-compatible computers can be
broken down into four distinct
components:
• BIOS Module
• Kernel
• Command Processor
• External Commands

30. • The BIOS Module
• The BIOS module includes the default resident drivers for:
• Console display and keyboard (CON)
• Line printer (PRN)
• Auxiliary device (AUX)
• Date and time (CLOCK)
• Boot disk device (block device)
• It also accomodates installable drivers (DEVICE=commands in
CONFIG.SYS), such as:
• MOUSE.SYS
• ANSI.SYS
• 386EMM.SYS
• CLOCK.SYS, etc.

31. The DOS Kernel
• The DOS Kernel performs the following functions:
• File and record management
• Memory management
• Character device input/output
• Spawning other programs
• Access to real-time clock
• The DOS kernel components are contained in the
MSDOS.SYS (or IBMDOS.COM) system file. Programs
communicate with the kernel via software interrupts.

32. The Command Processor
• The command processor is also known as the
shell, or the command interpreter.
• The command processor is responsible for
parsing and carrying out user commands,
including the loading and execution of other
programs from disk
• The command processor also includes the
code for many of the most commonly-used
DOS commands, known as the internal
commands.

33. • Thank You