PC Operations NC II/
Computer Education I
Mrs. Lanie P. Plecerda
MSWord - Wordprocessing
MS Excel – Spreadsheet application
MS Powerpoint – Presentation
Internet – Email and search the web
Computer – a machine that performs tasks,
such as calculations or electronic
communications, under the control of a set
of instructions called a program.
Elements of a Computer System
1. Human Resources
Elements of a Computer System
Human Resources – are required to perform the
planning, operations, and some of the controls
external to the physical computer. Ex. Computer
Operator, System Analyst and Computer
Hardware – refers to the physical components of a
computer system or an electronic components that
make up the computer system.
Software – is intangible and can only be seen but not
felt. It is an instruction that tell a computer exactly
what to use and what sequence of operations to
perform with the data.
Major Hardware Components
CPU – is the heart and brain of the computer.
It allow the computer to “think” about the
Memory – is classified either as primary and
I/O Devices – these are devices attached to
the main unit to facilitate communication (or
interface) between the user and the
Three Main Components of CPU
1. Control Unit – which is responsible for
maintaining order among the hardware
components. It acts like a traffic director; it
controls and directs the flow of information
between the input/output units and the central
2. ALU (Arithmetic Logic Unit) – which is
responsible for manipulating the data as required. It
contains all the electronic circuits for performing
the arithmetic calculations and logical comparisons.
3. Registers – which serve as temporary storage
areas for data during processing.
a. Firmware – is software stored permanently in
chips in the computer’s circuitry making in
unalterable by computer users.
b. Operating System – Ex. DOS, Windows XP
c. Application Software – is software that
performs a specific task such as word
processing, spreadsheet design or database
d. System Software – is software that is used to
operate and maintain a computer system.
Light pens are electronic pointers that allow users to modify designs on-screen. The hand-held
pointer contains sensors that send signals to the computer whenever light is recorded. The
computer’s screen is not lit up all at once, but traced row-by-row by an electron beam sixty
times every second. Because of this, the computer is able to determine the pen’s position by
noting exactly when the pen detects the electron beam passing its tip. Light pens are often used
in computer-aided design and computer-aided manufacture (CAD and CAM) technology because
of the flexibility they provide. Here, an engineer uses a light pen to modify a technical drawing on
a computer display screen.
A personal computer (PC)
enables people to carry out an
array of tasks, such as word
processing and slide
presentations. With a
connection to the Internet,
users can tap into a vast
amount of information on the
World Wide Web, send e-mail,
and download music and
videos. As a family tool, the PC
may be used for school,
record keeping, work, and
A typical computer system consists of a central processing unit (CPU), input devices, storage
devices, and output devices. The CPU consists of an arithmetic/logic unit, registers, control
section, and internal bus. The arithmetic/logic unit carries out arithmetical and logical operations.
The registers store data and keep track of operations. The control unit regulates and controls
various operations. The internal bus connects the units of the CPU with each other and with
external components of the system. For most computers, the principal input device is a
keyboard. Storage devices include external floppy disc drives and internal memory boards.
Output devices that display data include monitors and printers.
ROM (Read Only Memory) – is non-volatile
since its contents are not erased when the power
RAM (Random Access Memory) – is volatile,
its contents are lost when power is off, thus the
need for secondary storage where documents
and resulting information can be stored.
Primary - it is a storage which is immediately
accessible to the computer.
Secondary – holds data for a long period of
Three Basic Operations
INPUT – computer is supplied with
necessary data and processing
PROCESSING/COMPUTING – the
input data is processed and the answers
computed accordingly to the
OUTPUT – the answers or results are
reported back to the computer user.
Characteristics of a Modern Computer
2. Internal storage – used for storing both the
computer program and data being
3. Stored Program – the program of
instructions which stipulates the sequential
operations that the computer is to carry
4. Program modification – ability to
automatically modify a program.
Advantages of Using a Computer
1. Speed – it saves a tremendous amount of time
2. Accuracy – if the computer is properly programmed and
provided with accurate data, it will do the intended work
with unerring accuracy.
3. Reliability – can work almost twenty-four hours a day
with a little time-out for equipment check up and
4. Retention – can store and save massive files of data and
5. Economy – the per unit cost of processing data or doing
computations by computer considerably lower than by
6. Versatility – can used to solve a wide variety of problems
that arise in science and business.
Limitations of Computer
a. Dependence on People – it can only execute the
precise instructions that human beings provide.
b. Time-consuming and programming work – it is
unproductive until it is given the program that tells it
what operations to perform.
c. Disruptiveness – the results can reduced morale,
alienation, confusion and even sabotage.
d. Robot-like Processing – it is a big dumb machine,
dependent entirely on those who control it.
e. Computer Security – other security systems are
computer controlled, responding to specific pre-
recorded voice commands or physical characteristics lie
Kinds of Computer
General Purpose Computer – used for a
wide variety of applications such inventory,
payroll, accounting, market research and sales
Special Purpose Computer – incorporated
many features of general purpose computers
but support highly specialized data processing
tasks. Ex. Navigational computer on an