COMPUTER FUNDAMENTALS : COMPUTER FUNDAMENTALS
FUNDAMENTALS : FUNDAMENTALS Intro: The term “computer” comes from the word “compute” which means to calculate. So, a computer is considered to be a calculating device that can perform calculations at great speed and with very much accuracy. Computer takes raw data as input, processes it, and produces useful information as output. Input Processing Output
INPUTTING : INPUTTING Inputting is the process of entering data and instructions into the computer.
KEYBOARD : KEYBOARD The typewriter-like set of keys used to input data and instructions to the computer. Most keyboards use a QWERTY layout, and also have a calculator-like numeric keypad on the right side, as well as a set of cursor-movement keys. There are a total of 104 or more keys in a keyboard. Following are the types of keys:
TYPES OF KEYS : TYPES OF KEYS Numerical Keys: 0 to 9 Alphabetical Keys: A to Z Function Keys: F1 to F12. These keys are programmable that can perform special tasks assigned by the current application program. There are many other keys like Ctrl, Alt, Caps Lock, etc. which you will learn to use during practice.
MOUSE : MOUSE A small input device with one ore more buttons used for pointing or drawing. As you move the mouse in any direction, an onscreen mouse cursor follows the mouse movements. Once the mouse pointer is in the correct position on the screen, you can press one of the mouse buttons to initiate an action or operation; different user interfaces and file programs interpret mouse click in different ways.
SCANNER : SCANNER Used to scan images like photographs, logos, text, etc. and copy them in the computer. You can scan both colored and black and white images.
PROCESSING : PROCESSING Processing means performing arithmetical and logical operations on data. It is done by CPU (Central Processing Unit), also known as the brain of the computer. Arithmetical operations include addition, subtraction, division and multiplication. Logical operations include comparisons which result in some logical value, i.e. true or false. Like is a>50 and a<100.
CPU : CPU CU (Control Unit) ALU (Arithmetic Logic Unit) Memory
CU (Control Unit) : CU (Control Unit) Control the sequence in which various operations like inputting, storage, processing, outputting, etc. are to be performed by the computer.
ALU (Arithmetic Logic Unit) : ALU (Arithmetic Logic Unit) It is responsible for all the arithmetical and logical operations of the computer.
MEMORY : MEMORY The memory in CPU is the fastest memory. This memory is divided into various types of registers. The other types of memories are RAM, ROM and Cache Memory which are outside the CPU. These are discussed in the following slides.
OUTPUTTING : OUTPUTTING Outputting is the process of getting useful information out of the computer.
MONITOR : MONITOR A video output device capable of displaying text and graphics. It can be colored or black and white. A CRT(Cathode-Ray Tube) monitor is just like the old-fashioned T.V. set. An LCD(Liquid Crystal Display) monitor is the newest one.
PRINTER : PRINTER It is used to print information stored in the computer on a paper. Such a printed copy is also known as ‘hard copy’. There are many types of printers, a few of which are discussed below:
DOT-MATRIX PRINTER : DOT-MATRIX PRINTER In it, the printer head moves back and forth on the paper with multiple thin print wires called hammers striking the ribbon and squeezing ink from it onto the paper. They print every character by putting dots on the paper using the hammers. That is why, they are called ‘dot-matrix’ printers. They are cheap, noisy and are use for lengthy reports like account books. They can have 9 or 24 pins and can print either 80 or 132 characters per line.
INKJET PRINTER : INKJET PRINTER It is used to print heavy graphics like photographs, formatted text, etc. It can print in color and black and white. It is little bit costly, has higher running cost, quiet and the printing quality is very good.
LASER PRINTER : LASER PRINTER It is very costly and is used to print heavy graphics in very good quality. It can also print in color and black and white.
STORAGE DEVICES : STORAGE DEVICES These are of two types: Primary: They include RAM, ROM and Cache Memory. They all are very fast but have very limited storage capacity. That is why we use Secondary storage devices. Secondary: They are comparatively slower than Primary storage devices. They include hard disks, floppy disks, CD-ROMs, etc. They retain their contents when the computer is shut off.
RAM (Random Access Memory) : RAM (Random Access Memory) This is a temporary storage area or in other words this is volatile. Data gets lost as soon as the computer is switched off. There are thousands of locations where computer can store data in RAM. Computer can select any location randomly (not in sequence) for storage or retrieval. That is why the word ‘Random’ has been used.
ROM(Read Only Memory) : ROM(Read Only Memory) This is a permanent storage area that is not washed away on switching off the computer. It is used for firmware(software stored in a chip) such as the BIOS(Basic Input/Output System) used in PC(Personal Computer).
CACHE MEMORY : CACHE MEMORY Pronounced as “cash”, improves the performance of the computer by storing the contents of frequently used memory locations and their addresses. When the processor references a memory address, the cache checks to see if it holds that address. If so, the information is passed to the CPU directly. It is faster than RAM.
FLOPPY DISK : FLOPPY DISK A flat, round, magnetically coated, plastic disk enclosed in a protective jacket. It is removable, and so can be used to distribute software, to transfer data from one computer to another and to keep multiple copies of important data. These are of two types: Mini Disk: Its capacity is 1.2 MB. Its size is 5.25 inches. Micro Disk: Its capacity is 1.44 MB. Its size is 3.5 inches.
HARD DISK : HARD DISK It is made of magnetic disc which spins around its center and has read/write heads above and below the disk near the surface. They are usually built into the drive and not meant to be removed. They can store data in bulk. It is the fastest Secondary storage device. Its comes in various storage capacities like 10, 12, 15, 18, 20…GB(Giga Bytes).
CD-ROM : CD-ROM It is made up of plastic. CD-ROM drive is use to read data from it. Its full form is Compact Disk – Read Only Memory. That is, data can only be read from it. Data cannot be removed or stored time and again. Its capacity is 650 MB approximately.
TABLE OF UNITS OF MEASUREMENTS : TABLE OF UNITS OF MEASUREMENTS BIT (Binary Digit): It means either 0 or 1 Nibble: Any combination of 4 Bits. E.g.: 1101, 0001, 1010, etc. Byte: Any combination of 8 Bits. E.g.: 00101001, 11101100, etc. Computer uses 1 Byte to store any character. Kilo Byte(KB): 1024 Bytes Mega Byte(MB): 1024 KB Giga Byte(GB): 1024 MB Tera Byte(TB): 1024 GB
PowerPoint Presentation : Hence the smallest unit is a BIT, it means computer stores everything in the form of BITs. So, we can say that the language of computer is ‘Binary Language’.
HARDWARE AND SOFTWARE : HARDWARE AND SOFTWARE Computer can be broadly divided into two things: Hardware Software
HARDWARE : HARDWARE All the tangible parts of the computer constitute its hardware. A few examples are CPU, printer, keyboard, monitor, hard disk drive, etc.
SOFTWARE : SOFTWARE Software is a broad term that can imply one or many programs(a set of instructions), and it can also refer to applications that may actually consist of more than one program. There are two types of software: Application Software System Software
APPLICATION S/W : APPLICATION S/W It is designed to perform a specific task, such as accounting, word processing, designing, etc. E.g.: Excel, Word, Corel Draw, etc.
SYSTEM S/W : SYSTEM S/W It is a program that makes up the operating system along with the associated utility programs. E.g.: MS-DOS, MS-Windows, Compilers, Interpreters, etc.
POWER MANAGEMENT DEVICES : POWER MANAGEMENT DEVICES Two commonly used power management devices are: CVT: Elaborated as “Constant Voltage Transformer”, it protects the sensitive parts of the computer from power fluctuations. UPS: Elaborated as “Uninterrupted Power Supply”, despite from protecting the computer from power fluctuations, it also keeps the computer running during power failure by using its batteries. We can extend the backup time of UPS by attaching additional batteries to it.