Introduction to Computing

Introduction to Computing

• Computers are becoming a universal machine in the 21st Century.
• Early computers were large and expensive, confined to laboratories and research institutes.
• Computer engineers exclusively programmed early computers.
• The basic applications were complex calculations in science and engineering.
• Computing is now embedded in almost every item, and its application is ubiquitous.
• Computing transcends science, engineering, communication, space science, aviation, finance, social sciences, humanities, the military, transportation, manufacturing, and extractive industries.
• Early computers accepted numeric data, but now they process multimedia like text, audio, and video.
• The combination of computer and communications technology resulted in Information and Communication Technology (ICT).
• ICT along with globalization has made basic computer knowledge essential.
• This course introduces students to the historical evolution of computers, basic components, and applications.
• The course is made up of seven modules organized into 15 study units.
• Module 1 covers understanding the computer: basic concepts, an overview, and classification.
• Module 2 covers computer hardware including hardware components and auxiliary equipment.
• Module 3 covers computer software.
• Module 4 covers programming the computer through computer languages, and basic principles of programming.
• Module 5 covers areas of application of computers in education, business, industry, and government.
• Module 6 covers numbering systems.

Definition of a Computer

• A computer is an electronic machine or device that accepts data, processes it, stores it, and changes it into information.
• This transformation aided by sets of instructions called programs, and output devices like printers.
• Input refers to (DATA).
• Output refers to (INFORMATION).

Definition of Data

• Data refers to facts about a person, object, or place, such as name, age, complexion, school, class, or height.
• Information is referred to as processed data or a meaningful statement, like net pay, examination results, or lists of successful job candidates.

Methods of Data Processing

• Manual method of data processing involves chalk, walls, pens, and pencils.
• Manual is Cumbersome, tiresome, boring, frustrating, and time-consuming.
• Reliability, accuracy, neatness, and validity may be affected by human error.
• Mechanical method of data processing involves typewriters, roneo machines, and adding machines.
• The mechanical operations are basically routine.
• Computer Method has major features such as steadily and continuously processed data, is quiet, allowing temp and permanent storage.
• The computer method allows errors to be neatly corrected, output reports can be decent, with graphs and diagrams, and enhance accuracy and reliability.

Characteristics of a Computer

• Speed
• Accuracy
• Storage
• Automatic operation
• Reliability
• Flexibility

Computing Systems

• A computing system is composed of the computer system, the user, and the operating environment.
• The computer system includes hardware and software.
• ComputerHardware has the input unit, the processing unit, and the output unit.
• Computer Software is a series of instructions that enables the computer tasks, or grouping.
• A program is a group of instructions to perform a task.
• Series of programs make up software.
• Computer programs are categorized into system software, utility software, and application programs.

Conclusion Module 1 Unit 1

• A computer is any electronic device used for various purposes that accepts and processes data to produce output
• The computer method of data processing offers advantages over manual and mechanical methods.
• The computing system is made of the computer system, the users and the computing environment.

History of Computers Introduction

• The computer has evolved over time, with landmarks and milestones.
• Evolution of computers can be categorized into generations based on achievements, though can be categorized as non-rigid.

A Brief History of Computers

• A complete history would include devices like the ancient Chinese abacus.
• Other inventions are The Jacquard loom (1805), and Charles Babbage's "analytical engine" (1834). It would also include analog and digital computing architectures
• Mechanical devices like the Marchant calculator still found engineering applications in the 1960s.
• Analog computers solve systems of equations for oil reservoir modeling.
• Digital computing devices have the power, economics, and scalability to deal with large computations.
• Digital computers now dominate from hand calculators to supercomputers.
• Digital computing’s Evolution divided into generations based on technology, internal organization and programming languages/

First Generation Computers

• Manufactured between 1945-1949.
• Made of electronic valves (Vacuum Tubes) for the circuit
• Vacuum tubes required greater energy, generating high heat with memory.
• First Generation Computers occupied a large space and were comparatively slow.

Second Generation Computers

• These were manufactured between 1950-1960 using transistors.
• Second-generation computers were smaller, faster, less expensive, and emitted less heat than machines that have vacuum tubes.
• developed using transistors as memory, and made use of high-level languages.
• Second Gen Computers had higher speed of operation when compared to gen one.

Third Generation Computers

• They were manufactured between the late 1960s and early 1970 with integrated circuit replacing transistors.
• Integrated circuit (ICs) were developed in hardware, with a durable and faster build than prior generations.

Four Generation Computers

• These made during 1975-1990
• Era of Microprocessors and the evolution of Micro Computers.
• Fourth Gen computers are roughly 100 times smaller than the others.
• Fourth Gen computers are more powerful than prior generations.

Conclusion Module 1 Unit 2

• Computer development spans many generations, each with its achievements.

Unit 2 Summary

• The development has spanned thru four generations.

Module 1 Unit 3 Introduction

• The computer has evolved from mainframe computers to microcomputers.
• Computers have been classified based on different criteria.
• Unit 3 classifies computers based on three popular methods.

Classifying Computers

• Computers are classified based on: type of signal, purpose and size.

Classifying based on Signal Type

• There are three electronic computers which are Digital, Analog and Hybrid.
• Digital Computer represents variables in the form of digits, and deal with data, converted into binary form.
• Digital systems are best when dealing with discrete values (inventory control, invoicing and payroll).
• Digital computers are mostly used in commercial and business places.
• Analog Computer measures instead of counts, setting up a model of a system, and representing its variables in terms of voltage.
• Analog computers are used by scientists to solve systems of partial differential equations or are also used in continuous process control.
• Hybrid Computer is usually a special-purpose device for a specific task, that needs a conversion element for analog inputs and outputs digital values that are called digitisers.
• Hybrid computers give real-time response and deal with complex calculations and requiring a large memory.
• Hybrid are mainly used in aerospace and process control applications.

Classifying based on Purpose

• Computers are classified as for special or general use.
• Special-purpose computers are designed to solve a small list of problems and handle only one job.
• Operations that the computer follows may be built into the hardware with use in military purposes
• Computers solve navigational problems, tracking airplanes or missiles, process control applications in oil refinery, chemical manufacture or steel processing.
• Computers are used as robots in vehicle assembly plants and glass industries.
• General-purpose computers are designed to handle in a broad range, adequate by means of easily alterable instructions.
• Limitations imposed by memory, device type, speed.
• Areas where General purpose units are used consist of Payroll, Billing, sales analysis as well as cost counting and inventory control.

Classifying based on Capacity

• Capacity used to be measured in terms of physical size
• Today, size is not a good measure.
• Computers are categorized by cost and memory.
• Microcomputers (single board computers) are the cheapest, operating under normal conditions.
• IBM, APPLE, Compaq, Hewlett Packard (HP), Dell and Toshiba are examples.
• Personal computers are placed on the desk, hence desktop.
• Laptop, Notebook and Palmtop models are also available in microcomputers
• Versatility and speed describe PC’s, dealing in multiple sets at a time and attending several users.
• Computer Disadvantages are high costs in fragility, requirement to operate and needing special assistance programs to cool them.
• Mini Computers have memory capacity in between 128 to 256 Kbytes.
• Not costly, reliable and smaller as well, released in 1965 by digital equipment.
• WANG VS are examples.
• Mainframe Computes often called number crunchers that have up to 4 kilobytes of storage
• Mainframes execute 100 MIPS (Million instructions per Second). They have large systems used by many people.

Unit 3 Conclusion

• Computers are classified based on three criteria; signal, purpose, and size.
• If the goal is to process types of signals, hybrid devices are key.

Module 1 Unit 3 Summary

• computers can be classified based on three criteria, processing, and purpose.
• Based on size, computers can be mainframe, mini, or microcomputer.
• Based on the type of processes can be digital, analog, or hybrid units.
• Microcomputers are now offered due to differences in operation by voltage control to protect computers from power surges.