Architecture of Linux Operating System

• Kernel

The Linix kernel includes devices driver support for a large number of PC
hardware devices, advanced processor and memory management features, and
support for many different types of filesystems .

• Shells and GUIs

Linux supports two froms of command input: through textual command line shells similar to those found on most UNIX systems.(e.g. sh-the Bourne shell, Bash- the Bourne again shell and csh- the c shell) and through graphical inteface (GUIs) such as the KDE and GNOME window managers.

• System utilities
  

Virtually every systems utility that you would expect to find on standrad implementations of UNIX has been ported to Linux. This includes commands such as ls,cp,grep,awk,sed,bc,wc,more, and so on.

• Application programs

Linux distributors typically come with several useful application programs as standrad.

Linux Distributor

As Linux has become more popular, several different development streams or distributors have emerged, e.g.Redhat, slackware, Mandrake, Debian, and Cladera. A distribution compries a prepackaged kernel, system utilities, GUI interface and application programs.

Redhat is the most popular distribution because it has been ported to a large number of hardware platfroms, it is easy to use install and it comes with a comprehensive set of utilities and applications including the X windows graphics system, GNOME and KDE GUI environments, and the staroffice suite.

Open Source Nature of Linux

The open source nature of linux means that the source code for the linux kernel is freely available so that anyone can ad features and correct deficiencies.This approach has been very successful and what started as one persons project has now turned into a collaboration of hundreds of volunteer developers from around the globe. The open source approach has not just successfully been applied to kernel code, but also to application programs for linux.

A Brief History of UNIX

UNIX has been a popular OS for more then two decades because of its multi-user, multi-tasking environment,Stability, Portability and powerful networking capabilities.What follows here is a simplified history of how UNIX has develop.

What is an operaitng system ?

An operating operating system is a resource manager. It takes the form of a set of software
Routines that allow users and application programs to access system resources in a safe,efficient and abstract way.

The information systems Department

Information Systems:- A computer-based service, frequently a network system that provides information to users that may be operated by an organisation for its own benefit or offered to the public on a subscription basis.


Information Technology:The processing, storage, manipulation and distribution of information made possible by the convergence of the technologies of computing, microelectronics and telecommunication.

Major system

Software Package: A group of pre-written, fully tested and documented functional programs that one can buy for use on a computer to carry out application tasks. e.g. payroll, sales order processing.


Application Software: A specialised program or a series of programs that is a software package with associated documention, which performs a particular function, a specific task or job to meet a specific user need, e.g. company payroll,stock control syste, sales analysis reports.

Internetworking Basics

Networks and networking have grown exponentially over the last 15 years. They've had to evolve at light speed just to keep up with huge increase in basic mission critical users needs such as sharing data and printers as well as more advanced demands such as videoconferencing.
You can get a picture of a basic LAN network that's connected together using a hub. This network is actually one collision domain and one broadcast domain.

How Do You Become a CCNA?

The way to become a CCNA is to pass one little test(CCNA composite exam 640-802). Then-proof- you are a CCNA.(Dont you wish it were that easy?)

However, Cisco has a two-step process that you can take in order to become a CCNA that may or may not be easier than taking one longer exam.

The two-step method involves passing the following:

• Exam 640-822: Interconnecting Cisco Networking Devices 1 (ICND 1)

• Exam 640-816: Introduction to Cisco Networking Devices 2 (ICND 2)

What Skills Do You Need to Become a CCNA ?

To meet the CCNA certification skill level, you must be able to understand or do the following:

• A CCNA certified professional can install, configure, and operate LAN,WAN, and wireless access services securely, as well as troubleshoot and cinfigure small to medium networks for performance.

• This knowledge includes, but is not limited to, use of these protocols: IP, IPv6, EIGRP, RIP,RIPv2,OSPF,serial connections, Frame Relay, cable,DSL,PPPoE,LAN switching, VLANs, Ethernet, security, and access lists.
  

Why Become a CCNA ?

Cisco, not unlike Microsoft and Novell (Linux), has created the certification process to give administrations a set of skills and to equip prospective employers with a way to measure skills or match certain criteria.

The CCNA program was created to provide a solid introduction not only to the Cisco internetwork Oparating system(IOS) and Cisco hardware, but also to internetwork in general, making helpful to you in areas that are not exclusively Cisco's.

Cisco Certified Network Associate(CCNA)

The CCNA certification was the first in the new line of Cisco certification and was the pre-cursor to all current Cisco certification. Now you can become a Cisco Certified Network Associate for the coast of one test $150 & two test $125 each although the CCNA exams are extremely hard and cover a lot of material, so you have to really know your stuff.

Cisco is the king of routing,switching,and security, the microsoft of the internetworking world.The Cisco certifications reach beyond the popular certifications, such as the MCSE, to provide you with an indispensable factor in understanding todays network-insight into the Cisco world of internetworking. By deciding that you want to become Cisco certified.

The Business

Velotec is a medium sized manufacturing and retail services company, established twenty-five years ago. It has three main lines business.

• Producing car accessories and tuning equipment for the enthusiast. These are sold through a large number of retail stores and directly through a web site.

• Fitting new brakes and exhaust to cars through a chain of ten drive-in workshop that are owned by the company. These Workshop are all based in and around the capital city.

• Producing high technology components and assemblies for the automative industry, especially for motor racing.
  

Objectives

• Gain a business understanding of the systems development process.

• Define the range of roles and function in a typical system development project.

• Discuss the relationship between users, analysis and programmers and the need for clear agreement as to the users requirements.

• Specify the task and contribution of the members of a system project team.

• Describe the nature of the 'system life cycle' and the need for maintainable systems that have been developed and documented to defined standards.

• Apply the concepts of users-driven and user-friendly systems.
  

PS/2 Connector

PIN DIRECTION USED FOR REFERRED TO AS

1 Bidirectional Carrying key data DATA

2 Not Connected

3 Through Ground GND

4 Computer to keyboard Carrying +5 volts of
or mouse direct current VCC

5 Computer to keyboard
or mouse Clocking CLK

6 Not Connected

PS/2 Interface

Definition:
A PS/2 interface is how PS/2 devices are connected to the computer. The interface is composed of a PS/2 port on the computer, a device and a cable to connect the two together. PS/2 port are ports that are used to connect the keyboard and mouse to the computer. PS/2 ports are also referred to as a mini-DIN port. They are 6-pin round ports that are built in to the system. If ports are color coded, the keyboard port is purple and the mouse port is green.

PS/2 stands for personal system 2 which was an IBM computer.

Plug and Play

Plug and play (also written as PnP) is a standard that enables a PnP-compatible computer and a PnP-compatible operating system to work together to automatically configure setting when PnP-compatible hardware is connected to the system.

When you install hardware, this is a way high-level overview of what happens:

1. you connect a piece of hardware to a PnP-compatible system running a PnP-aware operating system.

2. All PnP cards enter configuration mode by enabling PnP code built into the card.

3. One at a time, PnP cards are isolated and a handle is assigned to the card. The handle us
used to identify that card.

4. Resources are allocated to each card that dont conflict with resources allocated to any other
card.

5. All PnP cards are activated and exit configuration mode.

Adjust Video Settings

To adjust the video setting for a monitor:

1. Use the control buttons located on the physical monitor to adjust:

• Vertical display position.

• Horizontal display position.

• Display height.

• Display widht.

2. Use the control buttons located on the physical monitor to adjust brightness and contrast.

3. Use the windows display properties dialog box to adjust user preference for screen
Resolution.

4. Use the windows display properties dialog box to adjust user preference for font size.
There are a couple of methods to do this.The first is usually sufficient for most needs.

Install a Monitor

To install a monitor:

• Turn off the computer.

• Locate the monitor port on the computer

• 15-pin VGA adaptar.

• Align the pins on the monitor cable with the holes in the adapter port and plug in the monitor.

• Secure the monitor to the port by tightening the screws on each side of the port.

• Plug in the monitor power cord.

• Turn on the computer.

• Turn on the monitor.

• Verify that the monitor works,
  

*Check the power light is on, that is green,that it is not blinking.

*Make sure the colors display correctly .

*Make sure there are no lines in the image displayed on the monitor.

*There should be no waviness to the display.

Display Characteristics

Characteristic Description

Dot pitch: The distance between the same color dots on the screen.The
Closer the dots are together, the smoother the image will be and
The finer the detail that can be shown.

Resolution: The maximum number of pixel on a monitor.

Refresh rate: The number of times per second that the entire monitor is
Scanned.

Color depth: The number of bits used to store the color of a pixel
Determines how many colors can be displayed.

Font: Changing to another font requires that the fonts be installed
On the system and the system to be restarted before they
Can be used.


Setting Description

Brightness If the brightness is set too high, you might get an "auro"
Effect displayed on the screen. if it is set too low, you might
Not see anything on the screen.

Contrast If the contrast is not set correctly for the monitor and the
Lighting conditions in the room you might not be able to see
Anything on the screen.

Image position This is the location of the display in relation to the physical
Monitor sometimes the image is not centered on the monitor.

Distortions If lines dont appear straight on the monitor, you might need
To adjust settings.

PORTS

Definition:

A port is a hardware connection interface on a computer system that enables devices to be connected to the system. All ports:

• Connect a device that uses a cable that matches the configuration of the port.

• Carry the signals from a device to the computer system.

• Carry the signals from the computer system to a device.

Ports Vary by :

• The number of pins or connections it contains.

• The layout of the pins.

• The signals they carry.

• The devices that can be connected to the port.

• The location.Some connect internal devices and other connect external devices.

Example:
A monitor port is a 15-pin female connector. The monitor cable ends in a matching
15-pin mule connector which plugs into the port on the system.

Gender:
Cables and port have genders. For example, if the port has plugs . the matching cable
will have sockets.The port in this case would be considered female and the cable would
be considered male.

Video Output Devices

Definition:-
A Video output device is a computer peripheral that users to view information
On a computer system. Similarities between video output devices include:

• All video output devices display an image of some type.
• They all have controls to change the settings for the device.
• They connect to the computer system using a cable.

Differences between video output devices include:

• The size and shape of the display.Monitors are measured diagonally across the glass screen.

• The location and type of controls. Controls could be separate buttons for each function.

• Some have a curved screen and others have a flat screen.

• some use analog signals and some use digital signals. Analog signals are carried on 15-pin VGA cables to the video port on the computer.

• Some use Cathode Ray Tube(CRT) technology and others use Liquid Crystal Display(LCD) technology

• The way they produce the image varies:

1. CTRs use a Phosphorous coating inside a glass screen
2. LCD monitors use different colored sandwiched between two sheets of plastic.

Peripheral Device

Define Peripherals as any device connected externally to the system case.

Example:- Monitor,Keyboard,Printer, Scanner, and any other device you can connect to one of the system connectors.