Wednesday, 8 August 2012

THE COMPUTER COMPONENTS

INPUT

SCANNER
MOUSE
KEYBOARD

WEBCAM

OUTPUT
PRINTER

SPEAKER







LCD MONITOR

STORAGE
RAM

ROM


PEN DRIVE



MICRO SD CARD



Sunday, 5 August 2012

The Family of Computers

THE PERSONAL COMPUTER

PC's is a small, single-user computer. This computer depends on a microprocessor. 

THE WORKSTATION COMPUTER.


This is a single-user computer. Although it has many monitors, but it is controlled by one person only ! It is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.

THE SUPERCOMPUTER !


This computer works just like its name. This is an extremely fast computer that can perform hundreds of millions of instructions per second. No computer can defeat the speed of this computer !

THE MINI COMPUTER.


This is the Logitech diNovo Mini Computer. It is a multi-user computer capable to support from 10 to hundreds of users simultaneously. Although it is small, the function of this mini computer were not as mini as their name are !

THE MAINFRAME COMPUTER.


This is a powerful multi-user computer. This owns the capability to support many hundreds or thousands of users at one time. Usually this mainframe computer were used at factories or military bases. 









Computer Geschichte ( The History of Computer )

The computer as we know it today had its beginning with a 19th century English mathematics professor name Charles Babbage.He designed the Analytical Engine and it was this design that the basic framework of the computers of today are based on.Generally speaking, computers can be classified into three generations. Each generation lasted for a certain period of time, and each gave us either a new and improved computer or an improvement to the existing computer.


First generation: 1937 – 1946 - In 1937 the first electronic digital computer was built by Dr. John V. Atanasoff and Clifford Berry. It was called the Atanasoff-Berry Computer (ABC). In 1943 an electronic computer name the Colossus was built for the military. Other developments continued until in 1946 the first general– purpose digital computer, the Electronic Numerical Integrator and Computer (ENIAC) was built. It is said that this computer weighed 30 tons, and had 18,000 vacuum tubes which was used for processing. When this computer was turned on for the first time lights dim in sections of Philadelphia. Computers of this generation could only perform single task, and they had no operating system. 





Second generation: 1947 – 1962 - This generation of computers used transistors instead of vacuum tubes which were more reliable. In 1951 the first computer for commercial use was introduced to the public; the Universal Automatic Computer (UNIVAC 1). In 1953 the International Business Machine (IBM) 650 and 700 series computers made their mark in the computer world. During this generation of computers over 100 computer programming languages were developed, computers had memory and operating systems. Storage media such as tape and disk were in use also were printers for output.




Third generation: 1963 - present - The invention of integrated circuit brought us the third generation of computers. With this invention computers became smaller, more powerful more reliable and they are able to run many different programs at the same time. In1980 Microsoft Disk Operating System (MS-Dos) was born and in 1981 IBM introduced the personal computer (PC) for home and office use. Three years later Apple gave us the Macintosh computer with its icon driven interface and the 90s gave us Windows operating system.
As a result of the various improvements to the development of the computer we have seen the computer being used in all areas of life. It is a very useful tool that will continue to experience new development as time passes.




This video may help you to understand more about computer history. You can find more at WWW.YouTube.Com

Wednesday, 1 August 2012

What is exactly the computer network ?

The computer network is the collections of two or more connected computers which people can share files and peripherals such as modems, printers, tape backup drives or CD-Rom drives.

Every network includes at least two computers Server or Client workstation. Beside that, each network also included Networking Interface Card's (NIC) and the most important is a connection medium, usually a wire or cable and wireless communication between networked computers and peripherals is also possible.

Every computer network included with Network Operating system software, such as Microsoft Windows NT or 2000, Novell NetWare and Linux.

How did the amazing computer works ?

Why is it important to know how a computer works?  Easy, if you don't, it will be hard to control.  Computers were never built to control us even though that is how it appears.  Their creation was just another tool God gave man to use to benefit society.  What can you do to learn more about computers?  I have an easy answer.  Just read, and use computers more.  They are not that hard and with time you too can become the master over this tool.
Computers, the ones we know and love have not been around all that long.  The first home personal computer was not sold until1977.  We have come a long way since then.  Did you know that in 1983 there were approximately 2 million personal computers in use in the United States.  However just 10 years later in 1993 the number had jumped to more than 90 million.  And now the number is in the hundreds of millions.
Computers, today are small, fast, reliable, and extremely useful.  Back in 1977 that really was not the case.  However, they both operated in basically the same way.  They both receive data, stored data, processed data, and then output data similar the the way our own brain functions.  This article deals with those 4 functions: Memory, Processing, Input, and Output.



Memory
Lets look at computer memory first.  The function of storage in a computer comes in many different sizes, types and shapes.  However there are two basic categories: short-term and long-term.  A typical computer contains numerous types of memory including RAMROMvirtualcache, and various long-term storage devices.  Each type of computer memory serves a specific function and purpose.Computer memory is measured in bytes.  A single byte is made up of a series of 1's and 0's normally traveling in pairs of eight.  These eight 0's and 1's are the way the computer communicates and stores information.  With each keystroke or character a byte of memory is used.  In another article you will learn more about bits and how the computer thinks.
Measuring Memory
Term/Byte
Abbreviation
Value
Bitnone0 or 1
ByteB8 bits  -example: 00100101
KiloK, KB1,024 bytes
MegaM, MB, Meg1,048,576 bytes (Million)
GigaG, GB, Giga1,073,741,824 bytes (Billion)
TeraT, TB, Tera1,099,511,628,000 bytes (Trillion)
Here is another way of looking at the measurement of memory:
Measuring Bytes
8 bits
=
1 byte
1000 bytes
=
1 kilobyte
1000 kilobytes
=
1 megabyte
1000 megabytes
=
1 gigabyte
1000 gigabytes
=
1 terabyte
 
ROM
ROM, or read-only memory is permanent, long-term, nonvolatile memory.  Nonvolatile means is doesn't disappear when the computer is shut off.  It also can not be erased or changed in anyway.  However there are types of ROM called PROM that can be altered.  The P stands for programmable.  ROM's purpose is to store the basic input/output system (BIOS) that controls the start-up, or boot process.
RAM
RAM, or random-access memory unlike ROM works only when the computer is turned on.  This memory is vital to the computer because it controls themoment by moment processes of the computer.  The first thing that goes into RAM is the OS (operating system) which is most cases is Windows 95.  Next for the RAM might be a game, or the Internet browser, or some type of software that you want to use.
Early personal computer only needed about 64K of RAM.  Today that number is drastically higher.  With photos, sounds, and even movies going into RAM, the amount need is now in the millions.  The computer I am currently using has 80 MB or 80,000K of RAM.
Multitasking has put more demand on RAM in the past few years.  Multitasking is the ability to run more than one program at the same time.  For instance, many people like to run Netscape Communicator along with their word processing software.  This means you need lots of RAM to hold both programs.
Other types of temporary memory are cache (pronounced "cash") and virtual memory.  Both of these types of memory supplement the computer's primary RAM and perform the same function as RAM.
Storage Devices:
RAM and ROM may be very important parts of the computer; however, without storage devices like hard drives and disk drives your computer would not be near as useful.
Here are the most common forms of Storage Devices found on your home computer:
 
Thumb Drive or Memory StickHard disk (drive) or HD
    A device that in 1998 IBM introduced and has caught on very quickly as a great portable storage device.  It quickly replaced the floppy disk. This small device is extremely reliable and fits in the USB port on your computer.  It come in sizes ranging from 1 GB to 64 GB in size.
    A stack of round metal platters called disks encased in a metal air tight shell.  They commonly range in sizes from 60  to 500 gigabytes (1000MB=1GB).  The hard drive's function is to store all the files, and software the computer will ever use.  Any file or software program used by RAM most likely will come from the disk drive. 
CD-ROM (Compact disk, read-only memory)DVD-ROM (digital video disk, read-only memory)
    CD's function much like hard drive in that they store large amounts of memory.  What separates them is their mobility and optical storage technology.  Their storage capacity is also very limited compared to hard drives.  The can only hold up to approximately 650 MB of information.  The other big difference is that you have to have a special drive to write to CD's.  Otherwise they can only be read from.
    DVD's are similar to CD in that they are written and read by laser.  Hard drives use magnetic currents store data.  However CD's and DVD's use light (laser) to write and read data on a disk.  These long and short pits are then stored or etched on the surface of the disk.  They can only be read by laser technology.  The new DVD technology increased the amount of memory a regular CD can hold.  DVD's can range in sizes from 4.34GB (1000MB=1GB)  to 7.95GB.

Processing
If someone had to find the brains of the computer they would most certainly say its the microprocessor.  The microprocessor is often referred to as the CPU (Central processing unit).  The microprocessor is a chip the size of a postage stamp.  The processor is the one part of the computer that is most important to the computer.  The microprocessor controls how data is sorted and directs the flow of data.To a great extent a computer is defined by the power of its microprocessor.  Chips with higher processing speed and more recent design offer the greatest performance and access to new technologies.  Most microprocessors made for PCs are made by Intel or by companies that clone Intel chips, such as Advanced Micro Devices (AMD) and Cyrix.
The early Intel chip came in models called 286, 386, and 486.  The 586 chip was given the name Pentium.  The series of Pentiums were given the following names:  Pentium ProPentium with MMX, and Pentium II.  The newer processors hold more transistors and thus more computing power on a single chip.
Microprocessor
Processor
No. of Transistors
Bus Width
80286
134,000
16 bit
80386
275,000
32 bit
80486
1,600,000
32 bit
Pentium
3,300,000
64 bit external/ 
32 bit internal
Pentium Pro
5,500,000
64 bit
Pentium w/ MMX
4,500,000
64 bit external/ 
32 bit internal
Pentium II
7,500,000
64 bit
The processor has come a long way and now some of the latest processors are: Celeron · Pentium Dual-Core · Core 2 · Core i5 · Core i7 · Xeon · Itanium  and who know what will come out next?
Input
One of the best features of a computer is the ability to give the computer commands and feed it information.  Without an input device this would not be possible.  Input devices can be built into the computer, like the keyboard in a laptop, or it can be connected to the computer by a cable.  The most common input device is thekeyboard.  There are lots of others such as: micetrackballstouch padstouch screenspensjoy sticksscannersbar code readersvideo and digitalcameras, and microphones.  In addition, storage devices such as disk drives can serve as input devices.

Output
Input is important but equally important is the ability to read what the computer is doing.  The computer output devices are used to serve the user.  The most common output device is the monitor, or screen.  However most computer come with speakers and a printer which are excellent output devices.  Storage devices such as disk drives and diskettes also serve as output devices when it is necessary to write new or updated data files to disk or tape. 

Hey ! Do you know what is computer system ?

First of all , what is a computer ? Computer is an electronic device that are programmed to store, retrieve and process data. In the specific words, computer is a device that can accepts digitalized data of information and manipulates it for some result based on a program or sequence of instructions on how the data will be processed. 

Then we'll go the main point . What is actually a computer system ? Computer system is system of interconnected computer that share a central storage system and various peripheral devices such as printers, scanners and routers. each computer that connected to the system can operate independently, but has the ability to communicate with other external devices and computers.