1. Computing System: Questions and Answers

b) Abacus

It uses beads on rods for basic addition and subtraction.

c) Charles Babbage

He designed a mechanical general-purpose computer in 1837.

b) Vacuum tubes

a) Transistor

b) Jack Kilby and Robert Noyce

This defines the third generation (1964-1971).

b) Control Unit

It directs the flow of data between functional units and interprets instructions.

a) Registers

d) SSD

An SSD is secondary storage.

b) 1,024 bytes

b) two years

d) Intel Core i7

a) Antivirus

b) Preparation

c) Richard Stallman

d) Manufacturer take-back programme

The others are unsafe methods.

Abacus.

Transistors.

Charles Babbage.

COBOL (and FORTRAN). These were high-level languages.

Fourth generation (1971 to present).

The CPU (Central Processing Unit), also called the processor.

Secondary memory (and ROM, which is non-volatile).

The ALU (Arithmetic Logic Unit).

Ultra Large Scale Integration.

1,024 bytes.

System software.

Linux (other examples: Ubuntu, Mozilla Firefox, LibreOffice, VLC Media Player).

Application software.

Richard Stallman (in 1985).

Data.

Information.

Processing.

Green computing (also called green IT).

E-waste (electronic waste).

E-waste.

In 1843, Augusta Ada Lovelace wrote the first algorithm intended for a machine, Charles Babbage's Analytical Engine. She is therefore regarded as the first computer programmer. Her work laid the foundation for computational theory.

• ENIAC: Electronic Numerical Integrator and Computer
• EDSAC: Electronic Delay Storage Automatic Calculator
• UNIVAC: Universal Automatic Computer

Artificial Intelligence (AI) is the ability of a computer or machine to perform tasks that normally require human intelligence, such as learning, reasoning, linguistic intelligence, perception and problem-solving.

The Control Unit (CU) acts like a traffic police man inside the computer. It directs the flow of data between the different functional units and interprets the instructions in programs.

Cache is a small, high-speed memory placed between the CPU and RAM. RAM is slower than the CPU, so the CPU would sit idle waiting for data. Cache stores copies of frequently accessed data from RAM, so the CPU finds data there first and is used more fully.

Word length is the number of bits a microprocessor can process at a time. For example, Intel 4004 is 4-bit, Intel 8085 is 8-bit, Intel 8086 is 16-bit, Intel 80386 is 32-bit and Intel Core i7 is 64-bit.

• Hard Disk Drive (HDD)
• Solid-State Drive (SSD)
• USB flash drive (pen drive)
• Memory card (SD card)
• External hard drive
• Optical disc (CD/DVD/Blu-ray)

A core is the physical processing unit within a CPU that executes instructions. A single-core CPU is like an office with one worker doing every job in turn. With more cores (dual, quad, hexa, octa-core), tasks run in parallel, giving much faster performance.

• SSI: Small Scale Integration (about 1 to 100 transistors per chip)
• MSI: Medium Scale Integration (100 to 1,000 transistors)
• LSI: Large Scale Integration (1,000 to 10,000 transistors)

The motherboard is the main printed circuit board of the computer. It acts as the backbone, providing power, connections and communication paths so all hardware components can work together. Components connected to it include the processor, RAM/ROM, storage devices, input/output devices and expansion cards.

A boot loader is a small program that runs every time a device is powered on. It loads the operating system into RAM after the Power-On Self-Test (POST). This process is called booting.

Stated by Intel co-founder Gordon Moore in 1965 (revised in 1975), Moore's Law observes that the number of transistors that can be economically placed on an integrated circuit doubles approximately every two years.

Clock speed is the number of pulses generated per second by the clock inside a computer. It indicates how fast the computer can execute instructions. It is now measured in Gigahertz (GHz), i.e. billions of pulses per second.

• Open source: Ubuntu, Mozilla Firefox, LibreOffice, Apache HTTP Server, WordPress
• Free software: GNU/Linux, GIMP, VLC Media Player, LibreOffice

• Freedom 0: freedom to run the program for any purpose
• Freedom 1: freedom to study how it works and change it
• Freedom 2: freedom to redistribute copies
• Freedom 3: freedom to distribute modified versions

A device driver is a software component that lets the operating system communicate with hardware devices. It works as a translator and bridge, converting OS commands into instructions the device understands and sending data back. Examples: a printer driver tells the OS how to send print jobs, and a graphics card driver enables display, resolution and 3D support. Keeping drivers updated is important for performance and stability.

Utility software manages, maintains and optimises the computer system's performance, security and disk organisation. Examples: antivirus software (protects against viruses and malware) and disk cleanup tools (remove unnecessary files).

Free software and open source are usually the same, but with different goals. The free software movement aims at social justice and user liberty, while the open source movement focuses on better software development. Free software grants four freedoms (run, study and change, redistribute, distribute modified versions), whereas open source makes the source code publicly available to view, modify and distribute under an open source license. Examples: GNU/Linux (free software), Mozilla Firefox and WordPress (open source).

Data is a raw, unorganised fact or set of facts such as numbers, text, images, audio and video. Example: exam scores 85, 92, 78, 95. Information is processed data. Example: the total score or average score calculated from those scores.

1. Collection
2. Preparation
3. Input
4. Processing
5. Storage
6. Output

Manual Data Processing (MDP) and Electronic Data Processing (EDP).

Computers perform every stage of data processing: input devices take in data, the CPU processes it, storage devices keep it, and output devices display results. They are widely used because of features such as speed, accuracy, storage, diligence, automation and versatility.

Green computing (green IT) is the practice of designing, manufacturing, using and disposing of computers and related subsystems in an eco-friendly and energy-efficient way. Two practices: energy efficiency (using energy-saving hardware and power management features) and waste reduction (extending the lifespan of devices to reduce e-waste).

E-waste contains hazardous substances such as lead, mercury, cadmium, bromine and arsenic. When improperly disposed of, these toxic substances dissolve into soil and groundwater, contaminating ecosystems and posing serious health risks to humans and animals. Workers handling e-waste without protection are also at risk.

• Energy efficiency: using less power for devices and data centres.
• Eco-friendly materials: designing devices with biodegradable, recyclable materials.
• Waste reduction: extending device lifespan to reduce e-waste.
• Responsible disposal: handling and disposing of old equipment properly and safely.

Improperly disposed e-waste releases toxic substances that contaminate soil and groundwater and harm plants, animals and humans. Protecting ecosystems through green computing and safe e-waste disposal ensures that technology benefits society without harming the environment.

1. First (1940-1956): vacuum tubes and magnetic drums; huge, hot, power-hungry; machine language. Examples: ENIAC, UNIVAC I, EDSAC.
2. Second (1956-1963): transistors; smaller, reliable, energy-efficient; COBOL and FORTRAN. Examples: IBM 1401, IBM 7090.
3. Third (1964-1971): integrated circuits by Jack Kilby and Robert Noyce; operating systems introduced. Example: IBM 360.
4. Fourth (1971-present): microprocessor (Intel 4004, 1971); GUI, PCs, laptops, mobile devices, the internet. Examples: Apple II, IBM PC.
5. Fifth (present and beyond): AI, parallel processing, quantum computing, DNA computing and IoT.

The computer follows the Von Neumann architecture (John Von Neumann, 1945), based on the stored-program concept: instructions and data are stored in the same memory unit.

1. The input unit accepts data and instructions and converts them into binary form.
2. The data and instructions go to the storage unit (primary memory: RAM, ROM, cache; secondary memory for long-term storage).
3. The CPU fetches them from memory. The Control Unit interprets the instructions and directs data flow, the ALU performs arithmetic and logical operations, and registers hold data temporarily.
4. Results are stored back in memory.
5. The output unit converts the results into human-readable form.

• Input unit: accepts data and instructions and converts them to digital (binary) form. Examples: keyboard, mouse, scanner, microphone, barcode reader, touch screen.
• CPU: the processor. It contains the Control Unit (directs data flow and interprets instructions), the ALU (arithmetic and logical operations) and registers (fastest storage inside the CPU).
• Storage unit: holds data and instructions. Primary memory (RAM, ROM, cache) and secondary memory (HDD, SSD, USB drives).
• Output unit: converts processed data into human-readable form. Examples: monitor, projector, speaker, printer.

Data is stored as bits (0 or 1). 4 bits make a nibble and 8 bits make a byte. Larger units: 1 KB = 1,024 bytes, 1 MB = 1,024 KB, 1 GB = 1,024 MB, 1 TB = 1,024 GB, then PB, EB, ZB and YB (each 1,024 times the previous). Memory is classified as primary (RAM, ROM, cache) and secondary (HDD, SSD, USB drives, memory cards).

• Word length: number of bits processed at a time (4-bit to 64-bit).
• Clock speed: pulses generated per second, measured in GHz.
• Number of cores: physical processing units in the CPU; multi-core processors run tasks in parallel.

• System software: controls and manages the hardware. Operating systems (Windows, Linux, Android), utilities (antivirus, disk cleanup), device drivers, firmware and language translators.
• Application software: performs specific tasks for the user. General-purpose (word processors, spreadsheets, browsers, DBMS) and special-purpose (accounting, reservation, inventory control, payroll systems).
• Programming tools: languages, translators (assembler, compiler, interpreter) and IDEs such as Python IDLE, Geany and Eclipse.

Utility software manages, maintains and optimises the performance, security and disk organisation of the computer, and supports its smooth functioning.

1. Collection: gathering raw data from sources such as sensors, surveys, transaction logs and documents.
2. Preparation: cleaning and organising data: removing duplicates, correcting errors and filtering irrelevant facts (GIGO).
3. Input: entering cleansed data into the computer using input devices.
4. Processing: the CPU performs calculations, comparisons, sorting, classification or summarising.
5. Storage: holding processed data in RAM temporarily or in secondary storage, cloud or databases permanently.
6. Output: presenting information in human-readable form: reports, graphs, printouts, audio or video.

• Speed: processes millions of instructions per second.
• Accuracy: errors are minimal if correct instructions and data are given.
• Storage: stores large volumes of data.
• Diligence: works for hours without getting tired or bored.
• Automation: performs tasks automatically once a program is given.
• Versatility: performs different kinds of work in every walk of life.

• Manual Data Processing (MDP): done by human effort with simple tools like pen and paper. It is slow and prone to errors.
• Electronic Data Processing (EDP): uses electronic devices like computers. It is the most common method today, and is highly efficient, fast and accurate.

E-waste is discarded electrical or electronic devices such as computers, mobile phones, televisions and printers. Rapid technological change makes people upgrade devices often, creating a massive amount of e-waste. It contains valuable materials (gold, silver, copper, palladium) and hazardous substances (lead, mercury, cadmium, bromine, arsenic). Improper disposal lets toxins enter soil and groundwater, contaminating ecosystems and posing serious health risks to humans and animals.

Green computing reduces the negative impact of technology on the environment by using energy-efficient hardware and power management, designing devices with recyclable and less harmful materials, extending device lifespans to cut e-waste, and ensuring responsible disposal. Together with safe e-waste disposal (recycle, reduce, proper disposal, educate), it ensures technology benefits society without harming the environment.