What is Computer?
ANS: A programmable
electronic device designed to accept data, perform prescribed mathematical and
logical operations at high speed, and display the results of these operations,
is called Computer.
Who is father of Computer?
ANS: Charles Babbage, an
English mechanical engineer and polymath, originated the concept of a
programmable computer, considered the father of the computer.
Computer has main four
parts
1. Input devices
2. Output devices
3. CPU
4. Memory
1. Input devices
When unprocessed data is
sent to the computer with the help of input devices, the data is processed and
sent to output devices. The input devices may be hand-operated or automated.
The act of processing is mainly regulated by the CPU. Some examples of input
devices are:
Example:
Computer keyboard
Digital camera
Digital video
Graphics tablet
Image scanner
Joystick
Microphone
Mouse
Overlay keyboard
Real-time clock
Trackball
Touchscreen
Light pen
2. Output devices
Output device is any piece of computer hardware equipment which converts information into human readable form.
Computer monitor
PC speaker
Projector
Sound card
Video card
The control unit, ALU, and
registers are collectively known as a central processing unit (CPU).
ALU
The ALU is capable of
performing two classes of operations: arithmetic and logic. The set of
arithmetic operations that a particular ALU supports may be limited to addition
and subtraction, or might include multiplication, division
CU:
The control unit (often
called a control system or central controller) manages the computer's various
components; it reads and interprets the program instructions,
transforming them into control signals that activate other parts of the
computeR.
REGISTER:
A processor register is a
quickly accessible location available to a computer's processor. Registers
usually consist of a small amount of fast storage
4. MEMORY:
In computing, memory is a
device or system that is used to store information for immediate use in a
computer or related computer hardware and digital electronic devices. The term
memory is often synonymous with the term primary storage or main memory. An
archaic synonym for memory is store.
IT
is two types
PRIMARY
MEMORY
It is again divided in two
categories
RAM
AND ROM
RAM IS Volatile memory is
computer memory that requires power to maintain the stored information.
The two main types of
volatile random-access memory (RAM) are static random-access memory (SRAM) and
dynamic random-access memory (DRAM).
ROM: Read only Memory
SECONDERY
MEMORY
You know that processor memory, also known as primary memory, is expensive as well as limited. The faster primary memory are also volatile. If we need to store large amount of data or programs permanently, we need a cheaper and permanent memory. Such memory is called secondary memory. Here we will discuss secondary memory devices that can be used to store large amount of data, audio, video and multimedia files.
Characteristics of Secondary Memory
These are some
characteristics of secondary memory, which distinguish it from primary memory −
It is large capacities to
the tune of terabytes
It is cheaper as compared
to primary memory
Depending on whether
secondary memory device is part of CPU or not, there are two types of secondary
memory – fixed and removable.
Hard
Disk Drive
Hard disk drive is made up
of a series of circular disks called platters arranged one over the other
almost ½ inches apart around a spindle. Disks are made of non-magnetic material
like aluminum alloy and coated with 10-20 nm of magnetic material.
CD
Drive
CD stands for Compact
Disk. CDs are circular disks that use optical rays, usually lasers, to read and
write data. They are very cheap as you can get 700 MB of storage space for less
than a dollar. CDs are inserted in CD drives built into CPU cabinet. They are
portable as you can eject the drive, remove the CD and carry it with you. There
are three types of CDs
CD-ROM (Compact Disk –
Read Only Memory) − The data on these CDs are recorded by the manufacturer.
Proprietary Software, audio or video are released on CD-ROMs.
CD-R (Compact Disk –
Recordable) − Data can be written by the user once on the CD-R. It cannot be
deleted or modified later.
CD-RW (Compact Disk –
Rewritable) − Data can be written and deleted on these optical disks again and
again.
DVD Drive
DVD stands for Digital
Video Display. DVD are optical devices that can store 15 times the data held by
CDs. They are usually used to store rich multimedia files that need high
storage capacity. DVDs also come in three varieties – read only, recordable and
rewritable.
Pen drive is a portable
memory device that uses solid state memory rather than magnetic fields or
lasers to record data. It uses a technology similar to RAM, except that it is
nonvolatile. It is also called USB drive, key drive or flash memory.
