SS1 Data Processing First Term Lesson Note

 

History of Computing

Meaning of Computing

• Computing is the process of using computers and other devices to solve problems, process data, and perform tasks.
• It involves activities such as calculation, data storage, retrieval, and communication.
• In simple terms, computing means using tools (manual or electronic) to handle information efficiently.

Importance of Studying the History of Computing

1. Understanding Development – It helps us see how computing has evolved from simple tools like the abacus to modern supercomputers.
2. Appreciating Technology – Knowing the history makes us value the effort and inventions of scientists and inventors who shaped modern computers.
3. Learning from the Past – Mistakes and successes from earlier stages guide improvements in present and future technologies.
4. Recognizing Impact on Society – The history shows how computing has changed communication, business, education, health, and almost every part of life.
5. Inspiration for Innovation – By studying past achievements, students and professionals can develop new ideas for the future.

 

 

Early Methods of Computation

Before modern computers, people used simple tools and methods to perform calculations. These early methods laid the foundation for today’s computing systems.

1. Counting with Fingers and Stones

• One of the earliest ways humans counted was by using fingers and small objects like stone, stick, cowries or shells.
• This method was simple but limited(have problems), especially when numbers grew larger.

2. Tally Marks and Number Systems

• Tally marks were straight lines drawn on wood, bones, or stones to keep count (//// = 5).
• Over time, formal number systems were developed, such as:
• Roman numerals (I, V, X, L, C, etc.)
• Arabic numerals (0–9), which we still use today.

The invention and adoption of Arabic numerals, especially the digit 0, greatly improved number representation. This development laid the foundation for the modern numbering systems used in mathematics and computing.

Examples of such numbering system used in computing are

• Decimal (Base 10): Uses digits 0–9. Commonly used by humans.
• Binary (Base 2): Uses digits 0 and 1. The language of computers.
• Octal (Base 8): Uses digits 0–7. Sometimes used as shorthand for binary.
• Hexadecimal (Base 16): Uses digits 0–9 and letters A–F. Often used in programming and computer memory representation.

Conversion between Number Systems

We can convert from one number system to another as follow

• Decimal ↔ Binary
• Decimal ↔ Octal
• Decimal ↔ Hexadecimal
• Binary ↔ Octal (by grouping in 3 bits)
• Binary ↔ Hexadecimal (by grouping in 4 bits)

Importance of Number Systems in Computing

• Computers process all information in binary form (0 and 1).
• Octal and hexadecimal make it easier for humans to read and write long binary numbers.
• Understanding number systems helps in programming, data storage, and digital electronics.

3. Ancient Mechanical Devices

To make calculations easier, inventors created early mechanical calculators:

• The abacus was invented around 2400 BC  China
• It used beads on rods to perform arithmetic operations like addition, subtraction, multiplication, and division.
• It is still used in some parts of the world for teaching arithmetic.

• Napier’s Bones (1617): Invented by John Napier, it used rods with numbers to simplify multiplication and division.
• Slide Rule (1620s)
• Invented by William Oughtred.
• Used for multiplication, division, roots, and logarithms.
• Remained in use until electronic calculators became common in the 1970s.
• Pascaline (1642): A mechanical calculator invented by Blaise Pascal. It could add and subtract directly.
• Leibniz’s Calculator (1673): Invented by Gottfried Leibniz, it improved Pascal’s design and could multiply, divide, and find square roots..
• Difference Engine (1822, Charles Babbage)

• A mechanical device designed to automatically compute mathematical tables.
• Considered one of the first steps toward programmable computers.

 

Pre-Modern Computing Devices

After early mechanical calculators, inventors created more advanced machines that influenced the design of modern computers.

1. Jacquard’s Loom (1801)

·         Invented by Joseph Jacquard.

·         A weaving machine that used punched cards to control patterns in fabric.

·         Important because it introduced the idea of programmable machines — the concept of instructions stored on cards influenced later computers.

2. Charles Babbage’s Analytical Engine (1837)

·         Designed by Charles Babbage (known as the “Father of the Computer”).

·         A mechanical, general-purpose computer that could perform many calculations automatically.

·         It had features similar to modern computers: input, processing, output, and storage.

·         Ada Lovelace wrote the first algorithm for it, making her the world’s first programmer.

3. Hollerith’s Census Machine (1890)

·         This is also called the punched card machine

·         Invented by Herman Hollerith to process the U.S. census.

·         Used punched cards to store and process data.

·         Made data processing faster and more accurate.

·         Hollerith’s company later grew into IBM (International Business Machines).

4. Burroughs’ Adding and Calculating Machine (1886)

·         Invented by William S. Burroughs.

·         A mechanical calculator mainly used in banks and offices for accounting.

·         Helped businesses process large amounts of numerical data efficiently.

 

Electromechanical Computers

Electromechanical computers were an important stage between mechanical calculators and fully electronic computers. They combined mechanical parts (like gears and switches) with electrical components to perform calculations.

1. Zuse Z3 (1941)

• Invented by Konrad Zuse, a German engineer.
• Considered the world’s first programmable digital computer.
• Used electromechanical relays for switching.
• Could perform general calculations automatically once programmed.

2. Atanasoff–Berry Computer (ABC) (1937–1942)

• Built by John Atanasoff and Clifford Berry in the USA.
• First electronic digital computer (though not programmable).
• Used binary numbers (0s and 1s) for calculations.
• Designed mainly to solve systems of equations.

3. Harvard Mark I (1944)

• Developed by Howard Aiken and built by IBM.
• Very large electromechanical computer (over 15 meters long).
• Used punched paper tape for input.
• Performed basic arithmetic (addition, subtraction, multiplication, division).
• Played a key role during World War II for scientific and military calculations.

4. Other Notable Electromechanical Computers

• Zuse Z4 (1945): An improved version of Z3, used after World War II.
• Colossus (1944): British computer used to break enemy codes during World War II.

The Von Neumann Architecture

The modern definition of a computing machine is indeed based on the stored-program concept, which is also known as the Von Neumann architecture. This concept was outlined in a 1945 p by John von Neumann, and his work is considered the foundation to modern computer design.

The Stored-Program Concept

This is the core principle that defines a modern, general-purpose computer. It states that both the program's instructions and the data it processes are stored together in the same electronic memory.

It outlines the five main components of a computer:

• Central Processing Unit (CPU): The "brain" of the computer that executes instructions.
• Main Memory (RAM): Stores both the program and the data.
• Arithmetic Logic Unit (ALU): Performs calculations and logical operations.
• Control Unit: Directs the flow of instructions and data.
• Input/Output (I/O) Devices: Allow the computer to interact with the outside world.

 

Generations of Computers

The history of modern computers is divided into five generations, each based on the technology used.

1. First Generation (1940s – 1950s)

• Technology: Vacuum tubes.
• Size: Very large, occupied entire rooms.
• Speed: Very slow, produced much heat, and consumed a lot of electricity.
• Storage: Used magnetic drums.
• Examples: ENIAC, UNIVAC.

2. Second Generation (1950s – 1960s)

• Technology: Transistors replaced vacuum tubes.
• Size: Smaller, faster, more reliable.
• Programming: Assembly language, early high-level languages (like COBOL, FORTRAN) was developed.
• Examples: IBM 1401, CDC 1604.

3. Third Generation (1960s – 1970s)

• Technology: Integrated Circuits (ICs).
• Features: Increased speed, reduced cost, smaller size.
• Usage: Became common in business and education.
• Examples: IBM 360 series, PDP-8.

4. Fourth Generation (1970s – 1980s)

• Technology: Microprocessors (thousands of ICs on a single chip).
• Features: Personal computers (PCs) were developed.
• Software: More advanced operating systems.
• Examples: Apple II, IBM PC.

5. Fifth Generation (1980s – Present)

• Technology: Artificial Intelligence (AI), advanced microprocessors, parallel processing.

·         Quantum computing

·         Cloud and edge computing

• Features: Very small, very fast, powerful storage, networking, and cloud computing.
• Examples: Modern laptops, smartphones, supercomputers.

 

 

Classification of Computers

Meaning of Classification of Computers

• Classification of computers means grouping computers into different types based on features such as size, purpose, data handling, or generation.
• It helps us understand the variety of computers and how each type is used.

Importance of Classification

1. Better Understanding – Makes it easier for students and users to learn about different types of computers.
2. Right Selection – Helps individuals, businesses, and organizations choose the right computer for their needs (e.g., a supercomputer for weather forecasting, a PC for personal use).
3. Shows Evolution – Explains how computers have changed over time, from large mainframes to small handheld devices.
4. Highlights Capabilities – Reveals the strengths and limitations of each class of computer.
5. Organized Study – Makes the study of computers more structured and systematic.

 

Classification of Computers by Size

1. Supercomputers

• The largest and most powerful computers.
• Can perform billions of calculations per second.
• Used for complex scientific research, weather forecasting, space exploration, and nuclear simulations.
• Example: Fugaku (Japan), Summit (USA).

2. Mainframe Computers

• Very large computers but smaller than supercomputers.
• Can handle large amounts of data and support many users at the same time.
• Commonly used by banks, airlines, insurance companies, and government departments.
• Example: IBM Z series.

3. Minicomputers

• Smaller and cheaper than mainframes.
• Can support multiple users but with less power than a mainframe.
• Used by medium-sized businesses, universities, and laboratories.
• Example: PDP-11.

4. Microcomputers (Personal Computers)

• The smallest and most common type of computers.
• Designed for one user at a time.
• Includes desktops, laptops, tablets, and smartphones.
• Used in schools, homes, offices, and for personal tasks.

 

Classification of Computers by Purpose

1. General-Purpose Computers

• Designed to perform many different tasks.
• Can run a wide variety of programs (word processing, spreadsheets, browsing, gaming, etc.).
• Examples: desktops, laptops, tablets, and smartphones.
• Common in schools, offices, homes, and businesses.

2. Special-Purpose Computers

• Designed to perform one specific task only.
• Faster and more efficient for that particular job.
• Examples:
• ATMs (for banking transactions)
• Traffic lights controllers
• Washing machine control systems
• Flight control systems

Classification of Computers by types (Data Handling)

1. Analog Computers

• Work with continuous data (not broken into separate steps).
• Often used for scientific and engineering purposes.
• Examples:
• Speedometers
• Thermometers
• Early weather forecasting devices
• Less common today because digital computers are more accurate.

2. Digital Computers

• Work with discrete data (numbers, letters, symbols).
• Use the binary system (0s and 1s) to process information.
• Most modern computers are digital.
• Examples: desktops, laptops, smartphones.

3. Hybrid Computers

• Combine the features of both analog and digital computers.
• Can process both continuous and discrete data.
• Examples:
• Hospital monitoring systems (measure body functions like heartbeat, then convert to digital data for analysis).
• Petrol pump systems.

 

 

Data and Information

1. Definition of Data

Data refers to raw facts and figures that have not yet been processed to give meaning.

It consists of facts and values that is usually unorganized and are not yet meaningful until it is processed. On its own, it may not be useful. Data is the basic input for processing.

Types of Data and examples

Data can exist in different forms:

·         Numeric Data:  Numbers (e.g., 120, 56.8).

·         Text Data: Words and letters (e.g., “School,” “Name”).

·         Audio Data: Sounds or voice recordings.

·         Video Data: Moving images and sound clips.

·         Image/Graphic Data:  Pictures, diagrams, or graphics.

·         Symbol Data: Special characters or icons (e.g., %, $, #, emojis).

Example: A list of phone numbers is meaningless until we know who they belong to.

 

2. Definition of Information

·         Information is the result of processed data that is organized and meaningful. Information carries meaning that can be understood, making it useful for decision-making.

·         Example: “The average score of the class is 64%” is information derived from the raw scores.

Qualities of Good Information

For information to be truly valuable, it must have these qualities:

·         Accuracy: It should be correct and free from errors.

·         Relevance: It must relate to the user’s needs.

·         Timeliness: It should be available at the right time.

·         Completeness: It should provide all the necessary details.

·         Clarity: It should be easy to understand and not confusing.

·                         Reliability: Should come from a trusted source.

·                         Adequacy: Should have just enough detail (not too much, not too little).

 

 3. Distinction between Data and Information

Feature	Data	Information
Meaning	Raw facts	Processed facts (meaningful)
Form	Unorganized (numbers, text, symbols)	Organized and structured
Usefulness	Not directly useful	Useful for decision-making
Example	1001, 1002, 1003	“Student IDs of class members are 1001, 1002, 1003”

 

Data Processing 1. Meaning of Data Processing ·         Data processing is the collection, manipulation, and transformation of raw data into meaningful information. ·         It involves different steps such as input, processing, storage, and output. ·         Example: Entering students’ marks into a computer, calculating the average, and generating a results report. 2. Purpose of Data Processing The main aims of processing data are: ·         To convert raw data into useful information. ·         To support decision-making (e.g., sales analysis for a business). ·         To improve efficiency by organizing and managing data properly. ·         To store and retrieve data for future use. ·         To reduce errors compared to manual handling. Stages of Data Processing 1. Data Collection ·         Gathering raw facts from different sources. ·         Example: Collecting student marks, sales records, or survey responses. 2. Data Preparation ·         Data preparation is the step where collected raw data is checked, cleaned, and organized before it is entered into the computer system. It involves ·         Editing: Checking for errors or mistakes in the data. ·         Coding: Giving data standard forms (e.g., Male = M, Female = F). ·         Validation: Confirming that data is correct and acceptable. ·         Sorting/arranging: Putting data in order (alphabetical, numerical, etc.). This ensures that only correct, complete, and usable data goes into processing. 3. Data Input ·         Entering the collected data into a computer system. ·         Done using devices like keyboard, mouse, scanner, or sensors. ·         Example: Typing marks into a spreadsheet. 4. Data Processing ·         Actual manipulation of data to make it meaningful. ·         Methods include calculations, comparisons, sorting, classifying. ·         Example: Calculating the average of student marks. 5. Data and Information Storage ·         Saving processed or raw data for future use. ·         Can be stored in files, databases, hard drives, or cloud storage. ·         Example: Storing student results on a school database. 6. Information Output ·         Presenting the processed data in a readable form. ·         Output can be softcopy (on screen) or hardcopy (printed). ·         Example: A report card or graph displayed on a screen.