This document defines a computer system and its basic components. It explains that a computer accepts data as input, processes it, stores the information, and outputs it. The three major components are hardware, software, and peopleware. It then discusses the central processing unit, memory units, input/output devices, and storage devices that make up basic computer hardware. The CPU contains an arithmetic logic unit and control unit that execute stored instructions. Memory includes volatile RAM and non-volatile ROM. The BIOS checks components at startup and loads the operating system. Input devices send data for processing while output devices display processed results.

1. COMPUTER SYSTEM -
INTRODUCTION
DON CAEIRO

2. DEFINITION
• COMPUTER is an electronic machine that follows a
set of instructions in order that it may be able to
accept and gather data and transform these into
information.

3. FUNCTIONS OF A COMPUTER
1. It accepts and gather data. (INPUT)
2. It processes data to become information. (PROCESSING)
3. It stores data and information. (STORE)
4. It presents information. (OUTPUT)

4. PROCESSING
SYSTEM
DATA INFORMATION

5. THREE MAJOR COMPONENTS OF AN
INFORMATION PROCESSING SYSTEM
• HARDWARE is the tangible part of a computer
system.
• SOFTWARE is the non-tangible part that tells the
computer how to do its job.
• PEOPLEWARE refer to people who use and operate
the computer system, write computer programs,
and analyze and design the information system.

6. BASIC UNITS OF MEASUREMENT
• BIT is a unit of information equivalent to the result of a
choice between only 2 possible alternatives in the binary
number system.
• BYTE is a sequence of 8 bits (enough to represent one
character of alphanumeric data) processed as a single unit
for information.

7. BASIC HARDWARE OF A PC SYSTEM
• Central Processing Unit (CPU)
• Memory Unit
• Input Devices
• Output Devices
• Secondary Storage Devices

9. BASIC HARDWARE OF A PC SYSTEM
• Central Processing Unit (CPU)
• Memory Unit
• Input Devices
• Output Devices
• Secondary Storage Devices

10. CPU – CENTRAL PROCESSING UNIT
• carries out the instructions of a computer program by
performing the basic arithmetical, logical, and input/output
operations of the system.
• Two Components
• ALU- arithmetic logic unit (performs arithmetic and logical operations)
• CU- control unit (extracts instructions from memory and decodes and
executes them)
• To execute a sequence of stored instructions called a program
• Four steps-

11. MEMORY – RAM AND ROM
• RAM is the memory available for the operating system,
programs and processes to use when the computer is
running.
• Requires a flow of electricity to retain data (e.g. the computer
powered on).
RAM is a type of volatile memory. Data in RAM is not
permanently written. When you power off your computer the data

12. • The memory that comes with your computer that is pre-written
to hold the instructions for booting-up the computer.
• Will retain data without the flow of electricity (e.g. when
computer is powered off).
ROM is a type of non- volatile memory. Data in ROM is
permanently written and is not erased when you power off your
computer.

13. BIOS
• basic input/output system
• integral part of your computer
• on an erasable programmable read-only memory (EPROM) chip
• determines whether all of the attachments are in place and
operational
• then it loads the operating system

14. INPUT AND OUTPUT DEVICES
• An input device sends information to a computer system for
processing.
• An output device reproduces or displays the results of that
processing.
• I/O devices
• OCR- barcodes

16. THANK YOU