Tuesday, 6 December 2011

NETWORKING COMMUNICATION MEDIUMS

Medium of Network
~ carries signal from one computer to another
~ may be physical cable
~may also be wireless
~ physical interfere : network interfere card (NIC) network adapter

Physical Media 
♥ Twisted-pair cable
~two independently insulated wires twisted around each other 

 
♥ Coaxial cable


~ insulated center wire grounded by a shield of braided wire
 
♥ Fiber-optic cable
~hundreds of clear fiberglass or plastic fibers

♥ ISDN line
~ special digital telephone line that transmits and receives information at very high speeds.


Wireless Media
~ Microwave system 
~ Satellite system
~ Cellular technology
~ Infrared technology

~♥~ BASIC NETWORKING CONCEPTS ~♥~

COMPUTER NETWORK

= Make two or more computer to able communicate each other by using this network.
= Computer network give some advantages by using it :
   ~ resources sharing : hardware, software.
   ~ information sharing : search capability (WWW)
   ~ promote communication & collaboration : email

3 Basic Concepts of Networking
♪♫ Topology - physical layout of networking 
♪♫ Protocol - rules in data communication
♪♫ Architecture - integrated hardware & software to form a working

3 Element in Data Communication
 

3 Characteristics in Data Transmission 
♥ Bandwidth

~amount of information that can be carried in a given time period (usually a second) over a wired or wireless communication link.
  
♥ Analog or Digital (type of signal)


♥ Serial & Parallel Transmission

Tuesday, 18 October 2011

SOFTWARE

=) Software is a collection of computer programs and related data that provide the instructions for telling a computerwhat to do and how to do it.

=) Software  also is a conceptual entity which is a set of computer programs, procedures, and associated documentation concerned with the operation of a data processing system.

=) Software also is a collection of computer programs together with the related data.

=) In other words software is a set of programs, procedures, algorithms and its documentation.

=) Computer Software can be organized into categories based on common function, type, or field of use.

CATEGORIES OF SOFTWARE

=) This sofware is divided into THREE:
  ~System Software
  ~Application Software
  ~Programming Software

SYSTEM SOFTWARE~a generic term referring to the computer programs used to start and run computer systems and networks.

APPLICATION SOFTWARE~ general designation of computer programs for performing user tasks.

PROGRAMMING SOFTWARE~translate and combine computer program source code and libraries into executable rams (programs that will belong to one of the three said categories).

Monday, 17 October 2011

COMPUTER ARCHITECTURE

=) Computer architecture is a practical art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals and the formal modelling of those systems.

Saturday, 15 October 2011

(✿◠‿◠) FIFTH GENERATION COMPUTER (now and future) (✿◠‿◠)

=) Fifth generations computers are only in the minds of advance research scientiets and being tested out in the laboratories. These computers will be under Artifical Intelligence(AI), They will be able to take commands in a audio visual way and carry out instructions. Many of the operations which requires low human intelligence will be perfomed by these computers.

=) Parallel Processing is coming and showing the possibiliy that the power of many CPU's can be used side by side, and computers will be more powerful than thoes under central processing. Advances in Super Conductor technology will greatly improve the speed of information traffic. Future looks bright for the computer.

 


 

♥●•٠•..Fourth Generation Computer (1974-Present) ::VLSI / ULSI ♥ ♥ ♥

VLSI - (Very Large-Scale Integrated)
ULSI - (Ultra Large-Scale Integrated)

@ This fourth computer generation is a combination of millions transistors
@ By the 1980's, very large scale integration (VLSI) squeezed hundreds of thousands of components onto a chip.
@  The ability to fit so much onto an area about half the size of a U.S. dime helped diminish the size and price of computers.
@ Then, the single-chip processor and the single-board computer emerged.

PERSONAL COMPUTER (PC)
=) This kind of computer was introduced in 1981.
=) It used in the home, office, and schools.
=) The number of this PC in used more than doubled from 2 million in 1981 to 5.5 million in 1982.

As computers became more widespread in the workplace, new ways to harness their potential developed.  As smaller computers became more powerful, they could be linked together, or networked, to share memory space, software, information and communicate with each other.

Monday, 3 October 2011

✿ ƸӜƷ✿ ~THIRD GERATION COMPUTER (1964-1974)~ ✿ ƸӜƷ✿

Despite the fact that transistors were clearly an improvement over the vacuum tube, they still generated a great deal of heat, which damaged the computer's sensitive internal parts.  The quartz rock eliminated this problem.  Jack Kilby, an engineer with Texas Instruments, developed the integrated circuit (IC) in 1958.  The IC combined three electronic components onto a small silicon disc, which was made from quartz.  Scientists later managed to fit even more components on a single chip, called a semiconductor.  As a result, computers became ever smaller as more components were squeezed onto the chip.  Another third-generation development included the use of an operating system that allowed machines to run many different programs at once with a central program that monitored and coordinated the computer's memory (Gersting 35 - 39).

    Fairchild Camera and Instrument Corp. built the first standard metal oxide semiconductor product for data processing applications, an eight-bit arithmetic unit and accumulator.  The fundamental components of this semiconductor laid the groundwork for the future discovery of the microprocessor in 1971.  Another company that took advantage of the third generation advancements was IBM with the unveiling of the IBM System/360.  The company was making a transition from discrete transistors to integrated circuits, and its major source of revenue moved from punched-card equipment to electronic computer systems.

    In 1969 AT&T Bell Laboratories programmers Kenneth Thompson and Dennis Ritchie developed the UNIX operating system on a spare DEC minicomputer.  UNIX was the first modern operating system that provided a sound intermediary between software and hardware.  UNIX provided the user with the means to allocate resources on the fly, rather than requiring the resources be allocated in the design stages.  The UNIX operating system quickly secured a wide following, particularly among engineers and scientists at universities and other computer science organizations.

*Microprocessor chips combines thousand of transistor,entire circuit on one compuer chip.
*Semiconductor memory
*Multiple computer models with different performance charactheristics
*The size of computer has been reduces drastically.
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