Operating System of the Computer including; I/O Management, OS/2-GUI, log file, Linux, Unix OS

1. Operating
System
LEC-05
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Syed Hamza Abbas

2. Operating system
• Group of short program which support the running of other
programs.
• Procedure which control the resources of computer; include
hardware, software, data and operator.
• Function performs as;
a) Manage the hardware and running programs.
b) Loading and managing the processes.
c) Provide basic user interface.
d) Loading, scheduling, initiating and execution of programs.
e) Allocating storage, I/O and other facilities of computer system.
f) Handling errors and restarts.
g) Maintaining a log file of computer operation.
h) Allocating memory for different tasks.
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3. LOG FILE
• Known as syslog that contains a record of the
operating system (OS) events that indicates how
the system processes and drivers were loaded.
• The syslog shows informational, error and
warning events related to the computer OS.
• By reviewing the data contained in the log, an
administrator or user troubleshooting the system
can identify the cause of a problem or whether
the system processes are loading successfully.
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4. Components of OS
1. Process Management.
2. I/O Management.
3. Memory management.
4. Storage Management.
5. Command Interpreter.
6. Protection.
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5. Process Management.
• Integral part of any modern-day operating system
(OS).
• must allocate resources to processes, enable processes
to share and exchange information, protect the
resources of each process from other processes and
enable synchronization among processes.
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6. I/O Management.
• how resources like processor and main memory are
managed.
• Humans interact with machines by providing information
through I/O devices.
• whatever a computer system provides services; is
essentially made available through specialized devices
such as screen displays, printers, keyboards, mouse, etc.
• Clearly, management of all these devices can affect the
throughput of a system. For this reason, input output
management also becomes one of the primary
responsibilities of an operating system. 6

7. Memory management.
• Two parts of the memory of computer.
1. Small part is used by OS.
2. Large part is used by user.
• Data sent to I/O devices, microprocessor has to wait for long
time due to speed slow of I/O devices.
• better to place memory and leave the processor for other
work.
• The program which manage the memory and its related
tasks are called memory management programs.
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8. Storage Management
• Provided data and programs to store permanent.
• Examples: Floppy , HDD, Flash Memory, etc.
• the computer system must provide secondary storage to
back up main memory.
• File Management:
• Data sent towards the I/O devices in form of “file”.
• All the logical and physical jobs related to file are carried
out by file management programs.
• Unique name assign to each file while OS define a file.
• Editing, deleting, updating, reading/writing done by file
management programs.
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9. Command Interpreter.
• A command interpreter is the part of a computer operating
system that understands and executes commands that are
entered interactively by a human being or from a program.
• some operating systems- called as sometime shell.
• Shell- graphically user interface,
• Use as CLI or GUI
• Out most layer of OS.
• Shells provide a way for you to communicate with the
operating system.
• When you log in to the system, the system locates the name of
a shell program to execute.
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10. Security
• Security refers to providing a protection system to
computer system resources such as CPU, memory, disk,
software programs and most importantly data/information
stored in the computer system.
• If a computer program is run by an unauthorized user,
then he/she may cause severe damage to computer or data
stored in it. So a computer system must be protected
against unauthorized access, malicious access to system
memory, viruses, worms etc.
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11. Famous OS
1) MS-DOS
2) OS/2
3) UNIX OS
4) MAC OS
5) LINUX OS
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12. DOS Commands
• MS-DOS stands for Microsoft Disk Operating System.
• Widely used throughout the world and designed for microcomputer and Laptops
computers.
• Easy to understand and use.
• Some of the most common commands are as,
• CD - changes the current directory (cd)
COPY - copies a file (cp)
DEL - deletes a file (rm)
DIR - lists directory contents (ls)
EDIT - starts an editor to create or edit plain text files (vi, vim, ed, joe)
FORMAT - formats a disk to accept DOS files (mformat)
HELP - displays information about a command (man, info)
MKDIR - creates a new directory (mkdir)
RD - removes a directory (rmdir)
REN - renames a file (mv)
TYPE - displays contents of a file on the screen (more, cat)
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13. DOS-GUI
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14. OS/2
• OS/2 is a series of computer operating systems, initially
created by Microsoft and IBM, then later developed by IBM
exclusively.
• Stands for "Operating System/2", because it was introduced as
part of the same generation change release as IBM's "Personal
System/2 (PS/2)" line of second-generation personal
computers.
• First version-1987
• and newer versions were released until December 2001.
• One user can execute several jobs on a single microprocessor-
multiprogramming.
• Widely used all type of microcomputer and laptops.
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15. OS/2-GUI
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16. UNIX OS
• Family of multitasking, multiuser computer operating
systems that derive from the original AT&T Unix,
developed starting in the 1971 at the Bell Labs research
center by Ken Thompson, Dennis Ritchie.
• Very sophisticated operating system and in very short
time it proved its capabilities, useful expanded from
micros to super supers.
• Can be installed where a number of users would like to
work together.
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17. UNIX GUI
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18. MAC OS
• MAC stands “Macintosh operating systems”.
• developed by Apple Inc. includes the graphical user interface-
based operating systems it has designed for use with
its Macintosh series of personal computers since 1984.
• 4.7 Mac OS X 10.5 Leopard.
• 4.8 Mac OS X 10.6 Snow Leopard.
• 4.9 Mac OS X 10.7 Lion.
• 4.10 OS X 10.8 Mountain Lion.
• 4.11 OS X 10.9 Mavericks.
• 4.12 OS X 10.10 Yosemite.
• 4.13 OS X 10.11 El Capitan.
• 4.14 macOS 10.12 Sierra.
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19. MAC GUI
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20. LINUX OS
• The Linux open source operating system, or Linux OS, is
a freely distributable, cross-platform operating system
based on Unix that can be installed on PCs, laptops,
notebooks, mobile and tablet devices, video game
consoles, servers, supercomputers and more.
• Popular Linux OS distributions include Ubuntu, Fedora,
Red Hat.
• Open Source - software for which the original source
code is made freely available and may be redistributed
and modified.
• Example: Internet web browser, APACHE Web server
and plenty of more.
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21. LINUX GUI
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22. Thank You…!!
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