The document is a lecture on the components of a computer system from Rajarata University of Sri Lanka's Faculty of Social Sciences and Humanities. It discusses the main internal and external hardware components, including the monitor, modem, system unit, mouse, speakers, printer, and keyboard. It also covers the software, liveware, and firmware that make up a computer system. The key hardware components discussed in more detail are the CPU, motherboard, input devices, output devices, storage devices, and RAM.

1. Introduction to Computer Studies
COMP 1112
Year 1 - Semester I
Lecture 04
– Components of computer system
Rajarata University of Sri Lanka
Faculty of Social Sciences and Humanities

2. Components of a Computer
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Faculty of Social Sciences and
Humanities

3. Components of a Computer
1. Monitor
2. Modem
3. System Unit
4. Mouse
5. Speakers
6. Printer
7. Keyboard
Faculty of Social Sciences and
Humanities

4. Computer system
HARDWARE
SOFTWARE
LIVEWARE
FIRMWARE
Faculty of Social Sciences and
Humanities

5. Hardware
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All the physical parts of the computer are known as
“Hardware”
Hardware falls in to 2 parts,
◦ Internal Devices
(CPU)
◦ Peripheral Devices/External Devices
(Input/output & Storage Devices)
Faculty of Social Sciences and
Humanities

6. Software
Programme instructions which controls and manage the
Hardware components are called “Software”. Computer HW
depends on software instructions.
 Software can be categorized in to 2 sections
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◦ System Software
◦ Application Software
Faculty of Social Sciences and
Humanities

7. Liveware
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All the human expertise in the computer System are called
Liveware
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Data Entry Operator
Graphic Designer
Web Designer
Network Engineer
Software Engineer
IT Manager
Systems Engineer
Faculty of Social Sciences and
Humanities

8. Firmware
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Special kind of programme (Software),which embedded in to
the Hardware components in order to communicate between
HW and SW.
◦ BIOS /ROM Chip
◦ Automatic Washing machine
◦ Automobiles Dashboard
Faculty of Social Sciences and
Humanities

9. Types of Hardware
Input Devices: devices that input Data into the
computer
 Output Devices: devices that output information
from the computer
 Storage Devices: devices used to store/record
data and information
• CPU (Central Processing Unit) : also called the
Microprocessor or “The Brain” of the Computer.
• Motherboard : The motherboard (main board,
system board) is a large circuit board which all
other PC components are connected
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Humanities

10. Categorization
Internal
CPU
Input
Devices
Hardware
External
Output
Devices
Storage
devices
Faculty of Social Sciences and
Humanities

11. List of Input Devices
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Keyboard
Mouse
Trackballs
Scanner
Barcode reader
Digital camera
Joystick
Microphone
Webcam
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Touchpad
Stylus
Touch Screen
MIDI keyboard
OCR
OMR
MICR
Faculty of Social Sciences and
Humanities

12. Faculty of Social Sciences and
Humanities

13. List of Output Devices
Monitor
 Printers (all types)
 Plotters
 Projector
 Speaker(s)
 Headphones
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Faculty of Social Sciences and
Humanities

14. Storage Devices
Alternatively referred to as storage, Memory, storage
media, or storage medium, a storage device is
a hardware device capable of holding information.
There are two storage devices used in
computers; Primary storage & Secondary storage
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Floppy diskette
CD
DVD
USB flash drive
Hard drive
Tape cassette
Flash memory cards
Faculty of Social Sciences and
Humanities

15. Faculty of Social Sciences and
Humanities

16. Primary Storage /Memory
RAM
ROM
SRAM
PROM
DRAM
EPROM
EEPROM
Faculty of Social Sciences and
Humanities

17. RAM (Random Access Memory)
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RAM is Primary Storage, also called internal storage.
Serves as computer’s workspace, storing all or part of the program that is
being executed, as well as data being used by the program.
RAM stores the operating system programs that manage the operation of
the computer.
RAM is Volatile storage/Memory:
 Power goes, data goes!
More memory = larger workspace
 Large programs = large number of instructions
 Measured in Bytes (KB, MB, GB, etc.)
Data/instructions are copied into memory as needed.
 Not enough memory or corruption of data/instructions in memory can
cause crash.
Two basic types of RAM are Dynamic RAM (DRAM), and Static RAM
(SRAM).
Faculty of Social Sciences and
Humanities

18. ROM (Read Only Memory)
ROM is nonvolatile. ROM chips contain permanently written
data, called firmware (your BIOS lives here).
 ROM contains the programs that direct the computer to
load the operating system and related files when the
computer is powered on.
 ROM chips are usually recorded when they’re
manufactured.
 ROM can be categorized in to 3 parts
◦ PROM
◦ EPROM
◦ EEPROM
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Faculty of Social Sciences and
Humanities

19. Comparison RAM Vs ROM
RAM
ROM
Faculty of Social Sciences and
Humanities

20. CPU (Central Processing Unit)
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Also known as the microprocessor, Processor
Central Processing Unit (CPU) is considered as the Brain of
the computer
It follows the instructions of the software (program) to
manipulate data into information.
The CPU consists of two parts
◦ Control unit and
◦ Arithmetic/logic unit (ALU)
Both the ALU and the CU contains registers, which are
◦ high-speed memory
◦ temporarily hold data and instructions during processing.
CPU Speed is measured by using Hz (Hertz) KHz,MHz,GHz.
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Humanities

21. Motherboard
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Humanities

22. Block Diagram of the Computer
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Humanities

23.  Questions
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Faculty of Social Sciences and
Humanities