Saturday, October 22, 2016

C language

C language

C is a general-purpose, imperative computerprogramming language, supporting structured programming, lexical variable scope and recursion, while a static type system prevents many unintended operations





What is program?

  A computer program is a sequence of instructions written using a Computer Programming Language to perform a specified task.


  The two important terms that we have used in the above definition are −

¡  Sequence of instructions
¡  Computer Programming Language

  To understand these terms, consider a situation when someone asks you about how to go to a nearby KFC. What exactly do you do to tell him the way to go to KFC?
  You will use Human Language to tell the way to go to KFC, something as follows −

¡  First go straight, after half kilometer, take left from the red light and then drive around one kilometer and you will find KFC at the right.
  Now, try to map the situation with a computer program.

  The above sequence of instructions is actually a Human Program written in English Language, which instructs on how to reach KFC from a given starting point.

  In case of computer programming we will write instructions in a programming language to do a particular task by the computer.
  A computer program can range from 2 lines to million lines of instructions.
  A computer without a computer program is just a dump box; It is programs that make computers active.

  Commonly used programming languages are.

¡  C,C++,Java,C#,Php,Python,Ruby,Perl etc.

Algorithm

  Algorithm is a set of instruction used to solve a particular problem in a generic logical language usually in the form of pseudocode.

Program

  Program is basically the implementation of that instructions in a programming language to do a particular task or to solve a problem.
  A typical programming task can be divided into two phases:

  Problem solving phase
¡  produce an ordered sequence of steps that describe solution of problem
¡  this sequence of steps is called an algorithm

  Implementation phase
¡  implement the program in some programming language
  First produce a general algorithm (one can use pseudo code)
  Refine the algorithm successively to get step by step detailed algorithm that is very close to a computer language.

Pseudo code

  Pseudo code is an artificial and informal language that helps programmers develop algorithms. Pseudo code is very similar to everyday english.
  Example: Write an algorithm to determine a student’s final grade and indicate whether it is passing or failing. The final grade is calculated as the average of four subjects marks.

Pseudo code:

  Input a set of 4 marks
  Calculate their average by summing and dividing by 4
  if average is below 50
                                Print “FAIL”
                else
                                Print “PASS”

Algorithm:

                Step 1:                  Input M1,M2,M3,M4
    Step 2:              GRADE ¬ (M1+M2+M3+M4)/4
    Step 3:              if (GRADE < 50) then
                                                                Print “FAIL”
                                                                else
                                                                                Print “PASS”
                                                                endif

High level languages

  A high-level language is a programming language such as C++,Java or Pascal that enables a programmer to write programs that are more close to human languages.
   Such languages are not directly understood by the computer and are translated into machiene language with the help of compilers and interpreters.

Mid level languages

  Mid level languages acts as an intermediate language b/w high and low level languages.
  It is called mid level because it is close to machiene as well as high level languages.
C is a kind of a mid level language.Programmer use it to do system programming for writing operating system as well as application programming.

Low level languages

  A low-level language is a programming language that deals with a computer’s hardware components and are machine oriented.
  These languages are directly understood by the computer because they are in the form of 0’s and 1’s.
  Examples of low-level languages are assembly and machine languages.
 
It is also called machine language or binary language.



   
106
 
Instructor: Fahad  Zia
 
 

Saturday, October 22, 2016 by Admin · 0

Friday, October 7, 2016

How to install windows 7


Following are the steps for the Installation of window 7

STEP 1: Boot from Windows 7 DVD. The first step is to place your Windows 7 DVD into the 
DVD tray and boot the machine. Your computer needs to be configured to boot from DVD.
This is done via BIOS. On most computers, the BIOS menu can be accessed by pressing
either the F2 or Del keys while the machine is booting.







STEP 2: Once you have completed this stage, Windows 7 will start loading. If you see the 
below image, you're doing well so far.






STEP 3: After a few moments, you will reach the installation menu. Now you have to choose 
the language and the keyboard.






STEP 4: Now you will be taken to the Install now menu. We have already prepared for the 
installation, so you can click Install now and proceed.







STEP 5: The next step is to accept the license agreement.




STEP 6:    After this, you will have to decide whether you want to Upgrade an existing 
installation or perform a Custom (advanced) installation, which is basically creating a new copy 
of Windows. Recommended you are to install a new copy. Fresh installations are always 
better. Your machine starts in a pristine state and does not rely on old leftovers.






STEP 7: Partitioning: The next step is to choose where you want to install Windows 7. This is 
probably the most important part of the entire installation, so you need to be very careful here 
and make the right choices.







STEP 8: We will create a new partition. According to official system requirements, Windows 7 
needs 16 GB of free space. However, you can do with less. The minimum recommended 
space for a partition where you want to place Windows 7 is 10350MB. Eventually, the 
installation itself will take approx. 7GB.







STEP 9: Windows 7 installer will now tell you that it will have to create an additional partition 
for the core system files. This will be a small primary partition ahead of your newly created 
one.








STEP 10: We now have a system partition and a primary partition, plus some free space. In 
purely technical terms, there is no such thing as a partition of the type system. There are only 
two types of partitions: primary and logical. The above-mentioned partition is a primary 
partition.
In total, there can only be up to four primary partitions on any physical disk. Windows 7, by 
itself, creates and uses at least two primary partitions. If we created another partition in the 
free space, it would too, become a primary partition.





STEP 11: Recommendation Use a third-party partitioning tool to create a partition layout 
beforehand. This will allow you to place Windows 7 files on a logical partition, saving yourself 
the precious commodity of wasting primary partitions on what is essentially non-system data.If you're using ONLY Windows 7 to create a partition layout on your system, then you should 
just create a partition with a sufficient size to hold the Windows 7 data files and nothing else.









STEP 12: Begin installation if you're comfortable with your setup, highlight the created 
partition and click Next. Windows 7 will be installed on this partition. Depending on your 
hardware, this can take some time. My testing shows approx. 30-40 minutes.








STEP 13: During the installation, your computer may restart several times. Let it be.
User settings eventually, you will be asked to provide your username and a computer name. 
You will also have to password-protect your account. This is most advisable. You should opt 
for a strong password.









STEP 14 Activation: The next step is to activate your Windows. Grab your key and type it 
here.







STEP 15 Updates: You will be asked to configure your updates. You can choose either setting 
you like. However, I recommend you configure this choice later, after Windows 7 is installed 
and running properly.












STEP 16 Time zone: Configure your time zone:








STEP 17 Network Location: Your location will determine the firewall settings for your newly 
installed Windows 7. You have three choices: home, work or public network. Home and work 
networks are supposed to be trusted, so you should not experience any problems adding other 
machines to your group or sharing data with them.
However, the public network is meant to be untrusted. So if you have installed Windows 7 in, 
let's say, Internet cafe, then you should choose the third option.



Window 7 has been installed.








Friday, October 7, 2016 by Admin · 0

Differentiate between software and hardware


Differentiate between software and hardware






by Admin · 0

Thursday, October 6, 2016

Computer hardwre


 Definition of Computer Hardware

Physical parts of computer are called hardware.

 History of Computer Hardware

Since civilizations began, many of the advances made by science and
technology have depended upon the ability to process large amounts of
data and perform complex mathematical calculations. For thousands of
years, mathematicians, scientists and businessmen have searched for
computing machines that could perform calculations and analyze data
quickly and efficiently. One such device was the abacus.
The abacus was an important counting machine in ancient Babylon, China, and throughout
Europe where it was used until the late middle ages.  It was followed by a series of
improvements in mechanical counting machines that led up to the development of accurate
mechanical adding machines in the 1930’s. These machines used a complicated assortment
of gears and levers to perform the calculations but they were far too slow to be of much use
to scientists.  Also, a machine capable of making simple decisions such as which number is
larger was needed. A machine capable of making decisions is called a computer.
The first computer like machine was the Mark I developed by a team from IBM and Harvard
University. It used mechanical telephone relays to store information and it processed data
entered on punch cards. This machine was not a true computer since it could not make
decisions.
In June 1943, work began on the world's first electronic computer. It was built at the University
of Pennsylvania as a secret military project during World War II and was to be used to calculate
the trajectory of artillery shells. It covered 1500 square feet and weighed 30 tons. The project
was not completed until 1946 but the effort was not wasted. In one of its first demonstrations,
the computer solved a problem in 20 seconds that took a team of mathematicians three days.
This machine was a vast improvement over the mechanical calculating machines of the past
because it used vacuum tubes instead of relay switches. It contained over 17,000 of these
tubes, which were the same type tubes used in radios at that time.
The invention of the transistor made smaller and less expensive computers possible.  Although
computers shrank in size, they were still huge by today’s standards. Another innovation to
computers in the 60’s was storing data on tape instead of punch cards. This gave computers
the ability to store and retrieve data quickly and reliably.

. Identify Types of Hardware


A generic term used to describe any component of a  computer system with a physical
presence and which can, therefore, been seen and touched.
Hardware components are often categorized as being input, output, storage or processing
components. Devices which are not an integral part of the  CPU are referred to as being
peripherals. Peripherals are usually used for input, storage or output (such as a  hard disk,keyboard or printer). A device does not necessarily have to be outside the same physical box
as the CPU. The best example of this is the hard disk, which is a peripheral even though it is
not usually housed within the main case.

Input devices are hardware devices which take information from the user of the computer
system, convert it into electrical signals and transmit it to the processor. The primary function
of input devices is to allow humans to interact with the computer system. For instance a mouse
allows the user to control the movement of the pointer (a common element in user interface
design).
Output devices take data from the computer system and convert it to a form that can be
interpreted by humans. For instance a monitor creates a visual electronic display to output
information created by the processor to the user.
Processing devices are the components responsible for the processing of information within
the computer system. This includes devices such as the CPU, memory and motherboard.
Storage devices are components which allow data to be stored within a computer system. This
includes devices such as hard disk drives and compact disk drives.

. Role of Hardware in Computer System

Computer hardware plays a vital role in computer system.
Hardware refers to the physical elements of a computer. Also referred
to as the machinery or the equipment of the computer. Examples of
hardware in a computer are the keyboard, the monitor, the mouse and
the processing unit However, most of a computer's hardware cannot be
seen; It's inside the computer case.
I/O lets the computer talk with the world around it. Sometimes it’s
necessary to add functionality to a computer to keep it up to date, or
make it better. The amount of I/O a computer has can be changed, by
adding expansion cards that support I/O. A graphics card can be added
to a computer to let it talk with a display, or a Wi-Fi card can be added,which will let a computer talk to other computers without a connecting wire. Sometimes
functionality can be added through a universal port, a port that supports multiple kinds of I/O.
USB, FireWire, and Thunderbolt (Types of I/O) support multiple data types. Your keyboard,
mouse, and monitor all connect to a computer's I/O.
CPUs or processors perform computations. They do the math for your calculator application,
they compare the size of numbers; people have likened the CPU to the "brain" of a computer.
Memory is what allows a computer to remember things. Similar to human memory, there's
long term memory (a hard disc or optical media (like a CD)) and short term memory (RAM).
When a computer is turned off, it forgets everything in the RAM, so the computer saves
everything it knows it will need later on in the long term memory. The short term memory is
easier to use because it can do I/O faster, so when a data is needed by the CPU, it's sent from
the hard disk drive (HDD) to the RAM. The short term memory lives on RAM, while the long
term memory is in the hard disk drive (HDD). Optical disks let you change certain parts of the
memory, it's kind of like having a book or notebook that you might read and get information
from.
Motherboard is a piece of hardware that makes connections in the right places between all
of the other components in a computer. It tells data where it should go. When the CPU finishes
processing some data, it might say to the CPU, OK, put this in the HDD, and the motherboard
will figure out where the HDD is and send the data there.

. Hardware Components in a Computer

System unit
Case that contains electronic components of the computer used to process data


Common Components Inside the System Unit

 Mother Board
 Processor
 Memory
 Adapter cards
o Sound card
o Video card
 Drive bays
 Power supply

1. Motherboard

Motherboard/system board is main circuit board of the system unit. It  Contains expansion 
slots, processor chips, memory slots and system Bus.




2. Slot for Processor:

This slot is used to add CPU.

3. Expansion Slots:

Expansion slots are used to add graphic cards, modems and networks cards.

4. Memory Slots:

Memory slot is used to add memory (RAM) in the computer.

What is memory?

Electronic components that store instructions, data, and result .Consists of one or more chips 
on motherboard or other circuit board Each byte stored in unique location called an address, 
similar to seats in a concert hall.

How is memory measured?
















Thursday, October 6, 2016 by Admin · 0

Define and Differentiate Software and Hardware


In this learning unit you will be introduced to hardware and software.
After completion of this unit, you will able to understand about: Definition
of software, History of software, Definition of hardware, History of
hardware,  Identify types of hardware, Role of hardware in computer
system, Identify Different hardware components in a computer ,Examine
hardware of a network, Compare software and hardware


1. Definition of Software

Software is a set of instructions that tells the computer what to do and how to do it.

2. History of Software

The term “software” was introduced in the late 1950s and was soon
adopted throughout the industry. Coined by statistician John Tukey, the
term became a catchall, user-friendly term for the work of computer
programmers who were using terminology ranging from “computer
program” to “code.”






by Admin · 0

Wednesday, October 5, 2016

History Evolution of Internet


Overview

In this learning unit, you will be introduced to basic concept of internet
and computer networking. After the completion of this unit, you will able
to understand definition of internet, comprehend working of internet,
history and evolution of internet.

1. Definition of Internet

Internet is Worldwide collection of networks that connects millions of
businesses, government  agencies, educational institutions, and
individuals. The Internet, sometimes called simply "The Net,"
The Internet is a global network connecting millions of computers across
the world to exchange information, news and opinions

2. Comprehend Working of Internet

How the Internet works:

The Internet works because open standards allow networks all over the world to interconnect.
How to connect?
Two ways to connect with internet


1-Slow-speed Technology

Modem in your computer uses a standard telephone line to connect to the Internet. Connection
must be established each time you log on.

2- High-speed Connection

DSL, cable modem, FTTP, fixed wireless, wireless modem, Wi-Fi, and satellite modems.
Connection is always on whenever the computer is running.



What are ways to access the Internet?

ISP (Internet service provider)

An Internet Service Provider (ISP) is a  company that gives you access to the Internet and
charge fee against it.







Wednesday, October 5, 2016 by Admin · 0

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