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Components of Data Processing

Data Processing
• A technique of collecting, manipulating and
distributing data to achieve certain
functions
• Its objective is to convert raw data into
information that can be used in decision
making

System
• Collection of objects, procedures, or
techniques that interact in a regulated manner
to form an organized whole
• Systems may be composed of smaller
assemblages of parts known as subsystems
• Each subsystem serves specific functions to
accomplish the function of a system as a whole

Computer Subsystems
• Central Processing
Unit
• Input/output
• Memory

Computer Subsystems
• Central Processing Unit
– Integrates and coordinates overall
operations
– Brain and heart of computer system
– Simply called as Processor
– Composed of three units
• Control Unit
• Arithmetic /Logic Unit (ALU)
• Primary Storage

Central Processing Unit

Central Processing Unit
• Arithmetic/Logic Unit
– Performs arithmetic computations
and logical operations

Central Processing Unit
• Primary Storage Unit
– Holds instructions, data, and intermediate and
final results
– A reusable, fast storage medium, directly
accessible by the control unit
– Each storage cell is capable of storing one bit of
data

Input/output Subsystems
• Provides the mechanism for
communications between the CPU and the
outside world
• Input subsystem – reads data and converts
them into electronic pulses
• Output subsystem – reports the results of
the processing by the CPU

Memory Subsystems
• Also known as the “Secondary storage”, allows
for extra data storage, exceeding the CPU’s
primary storage
...

• Retrieval time is slower than primary storage

I/O Components
• INPUT DEVICES
– An input device is any hardware device that sends
data to the computer, without any input devices, a
computer would only be a display device and not
allow users to interact with it

INPUT DEVICES
•
•
•
•
•
•
•
•
•

Keyboard
Mouse
Barcode
Digital camera
Paddle
Joystick
Microphone
Optical scanner
Webcam

I/O Components
• Output device
– Any peripheral that receives or displays output
from a computer

Output devices
•
•
•
•
•
•
•

Monitor
Flat-panel display
Printer
Projector
Sound card
Speaker
Video adapter

STORAGE COMPONENTS
• Memory – Several modes of memory access are used in the CPU
...

A user cannot modify a file if that file is stored on ROM
The term Write-Protected in some files are also considered as read only files
It is mainly used to distribute firmware (software that is very closely tied to
specific hardware and unlikely to need frequent updates)

STORAGE COMPONENTS
• Memory
– Programmable Read Only Memory (PROM)
• enables the user to add special information to the ROM
supplied by the manufacturer as part of the system

– Virtual Memory (VM)
• An imaginary memory area supported by the software
in conjunction with the hardware

STORAGE COMPONENTS
• Mass Storage Devices
– Magnetic Tapes
• It is a medium for magnetic
recording, made of a thin
magnetisable coating on a long,
narrow strip of plastic
...
44 megabytes of data, a
zip disk can hold around 100 megabytes of data
• This means that a zip disk can hold a lot more data which is useful in
today's computer market where software applications and files are
becoming bigger
• Files such as mp3 music files usually need to be saved on 2 or more
floppy disks whereas a zip disks can hold numerous mp3 files
•

STORAGE COMPONENTS
• Mass Storage Devices
– Compact Discs
• It is an optical disc used to store
digital data

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