This document provides an introduction to computer systems and fundamentals of information technology. It discusses the classification of computers based on the type of data processed (analog, digital, hybrid), functions performed (special purpose, general purpose), and processing capabilities (microcomputer, workstation, minicomputer, mainframe, supercomputer). It also defines computer storage capacities in bytes, kilobytes, megabytes etc. and describes measures of computer processing speed in milliseconds, microseconds, MIPS, MHz and GHz. Faster processing is indicated by higher numbers in these measures.

1. INTRODUCTION TO COMPUTER SYSTEMSTOPIC:
INTRODUCTION TO
INFORMATION TECHNOLOGY
FUNDAMENTALS

2. What this Learning Material is about?
This Learning Material contains the following lessons:
1. Classification of Computers
2. Computer Storage Capacities
3. Computer Processing Speed
What are you expected to learn?
This Learning Material contains the following lessons:
1. Classify computers according to data handled, functions
performed and processing capabilities.
2. Differentiate the computer storage capacities.
3. Identify computer processing speed.
How to learn from this Learning Material?
Here's a simple guide for you in going about this learning Material.
1. Set aside other tasks that will disturb you while enjoying the
lesson.
2. Take your time in watching, listening and reading the
content. You can download this file for your future reference.
3. Ask your parent/guardian to assists you in using this
Learning Material.

3. CLASSIFICATION OF COMPUTERS
• Types of data processed (Analog, Digital, and
Hybrid computers)
• Functions performed (Special Purpose and
General Purpose computers)
• Processing capabilities (Microcomputer,
Workstation, Minicomputer, Mainframe, and
Supercomputers)

4. TYPES OF DATA PROCESSED
Analog Computer
• It operates on inputs of continuously varying electrical voltage.
• It measures the input rather than counting.
• they measure continuous physical magnitudes (e.g. pressure,
temperature, voltage, current, length).
• Analog computers are powerful tools to solve differential
equations.

5. TYPES OF DATA PROCESSED
Digital Computer
• It operates essentially by counting.
• All quantities are expressed as discrete digits or numbers and
computations are done with numerical digits.
• Mathematical expressions are represented as binary digits (0 and 1) and
all operations are done using these binary digits at a very high rate.
• Digital computer is much faster than analog computer and the
computations are far more accurate.

6. TYPES OF DATA PROCESSED
Hybrid Computer
• Combine features of both analog and digital computers.
• In this computer, some calculations are done in the analog portion of the
computer and some are done in the digital portion of it.
• In a hospital, for example, analog devices may measure patient's heart
function, temperature and other vital signs. These measurements may
then be converted into numbers and supplied to a digital component in the
system. This component is used to monitor the patient's vital signs and to
send an immediate signal to the nurse's station if any abnormal readings
are detected.

7. TYPES OF DATA PROCESSED

8. CLASSIFICATION OF COMPUTERS
ACCORDING TO FUNCTIONS
PERFORMED
• SpecialPurposeComputer
―It is made specially to cater to the requirements of a
particular task or application, for example, weather
forecasting.
• GeneralPurposeComputer
―The general-purpose computer is designed to meet the
needs of many different applications.
―General-purpose machine can be used to prepare billing,
manage inventories, print sales reports, and do scientific
calculations and so on.

9. CLASSIFICATION OF COMPUTERS
ACCORDING TO PROCESSING
CAPABILITIES
• Minicomputer
• Microcomputer
―Portable Computer
―Personal Computer or Desktop Computer
• Workstation
• Mainframe
• Supercomputer

10. MINICOMPUTER
• It is a medium sized computer that is costlier and more
powerful than a microcomputer.
• They have many uses in business such as payroll
processing, process control, invoicing, and stock control.
They are mainly used as departmental computers in large
and medium-sized organisations.

11. MICROCOMPUTER
Microcomputer is the low end computer. It is built on a single chip
microprocessor.
Microcomputers include:
a) Portable Computer
― Portable computer is a very small, easy to use microcomputer.
― The users can carry it wherever they go.
― This group includes pen-based computer, hand-held computer, notebook
computer, laptop computer and mobile devices.
b) Personal Computer or Desktop Computer
― Personal computer is a microprocessor based, single user computer.
― The peripherals for personal computer include a keyboard and a mouse as
input devices, monitor to display information and a hard disk for storage.
― The personal computer is also called desktop computer as it is normally
installed on a desktop.

12. WORKSTATION
• A powerful computer which in terms of power is between
personal computer and minicomputer.
• It has high resolution graphics monitor, large RAM and
secondary storage.
• It is used for specialized applications such as desktop
publishing, software development and engineering designs.

13. MAINFRAME
• The earliest computers were called mainframes due to their
size.
• They have large storage capacities, very high speed of
processing (compared to micros and minis).
• It can support a large number of terminals (Many hundreds
to thousands) for use by a variety of users simultaneously.
• They are used by big companies, banks, government
departments, etc. as their main computer.

14. SUPERCOMPUTER
• It is the fastest and the most expensive computer.
• This has extremely large storage capacities and computing
speeds that are at least ten times faster than that of other
computers.
• These include applications in electronics, petroleum
engineering, weather forecasting, medicine and nuclear
energy research.

15. CLASSIFICATION OF COMPUTERS
ACCORDING TO PROCESSING
CAPABILITIES

16. COMPUTER STORAGE CAPACITIES
• Data is made up of individual elements that can have
only one of two states, the “ on” or “off” state.
• These elements are known as “bits” or “binary digits”
and can have values of either ‘1’ or ‘0’.
• Bits are grouped together to form a ‘byte’ which are
normally the smallest grouping used by computers.
•
• A byte is normally made up of 8 bits.

17. COMPUTER STORAGE CAPACITIES
The following are computer storage capacities:
Name Abbreviation Number of Bytes
Byte B 1 byte
Kilobyte KB 1,024 bytes
Megabyte MB 1,048,576 bytes
Gigabyte GB 1,073,741,824 bytes
Terabyte TB 1,099,511,627,776 bytes
Petabyte PB 1,125,899,906,842,624 bytes

18. COMPUTER STORAGE CAPACITIES

19. COMPUTER PROCESSING SPEED
A computer's processor speed describes the maximum number of calculations per
second the processor can perform. It is the rate at which a processor executes a
task
Computer speeds are categorized as follows:
Milliseconds – speed of processing is measured in thousands of a second.
Microseconds – speed of processing is measured in millions of a second.
Nanoseconds – speed of processing is measured in billions of a second.
Picoseconds – speed of processing is measured in trillions of a second.
MIPS – speed of processing is measured in millions of instructions per second.
Mhz (megahertz) – speed of processing is measured in millions of cycles per second.
Ghz (gigahertz) – speed of processing is measured in billions of cycles per second.
Note: A higher number of computer speed meant a faster processor.