Computer Architecture Fundamentals

• A computer is an electronic device, programmable to accept data (input), process it, and generate results (output)
• A computer system consists of hardware and software

Computer System Components

• Central Processing Unit (CPU)
• Memory
• Input/output devices
• Storage devices
• These components operate as one to produce the desired output
• Computer systems vary in form and size, from high-end servers to smartphones

Central Processing Unit (CPU)

• It executes the actual processing
• Referred to as the "brain" of the computer
• Can be placed on one or more microchips called integrated circuits (ICs)
• ICs are made of semiconductor materials
• Given instructions and data through programs
• Fetches program and data from memory
• Performs arithmetic and logic operations according to instructions
• Stores results back to memory

CPU Components

• Arithmetic Logic Unit (ALU)
• Control Unit (CU)

Registers

• Local memory in the CPU used for storing data and instructions during processing
• Registers are limited in size and number

Arithmetic Logic Unit (ALU)

• Performs arithmetic and logic operations as instructed by a program

Control Unit (CU)

• It controls sequential instruction execution
• Interprets instructions
• Guides data flow through the computer's memory, ALU, and input/output devices
• CPU is also known as a microprocessor

Input Devices

• Control signals are sent to a computer using input devices
• Converts input data into a digital form
• Examples: keyboard, mouse, scanner, touch screen, braille keyboards, voice input

Data Storage

• Data entered through an input device is temporarily stored in main memory (RAM)
• Permanent storage for future use is in secondary memory

Output Devices

• Receives data from a computer system and converts digital information into human-understandable form

• Used for display, physical production, etc.

• Examples: monitor, projector, headphone, speaker, printer

• Braille display monitors are useful for visually challenged users

• Printers are the most common device to get output in physical (hardcopy) form

• Common printer types include inkjet, laserjet and dot matrix

• 3D printers build physical replicas of digital 3D designs

Evolution of Computing Devices

• Computing devices have evolved from simple calculators to powerful data processors
• Key milestones:

Abacus

• A mechanical device that is capable of doing simple mathematics; invented around 500 BC

Pascaline

• Invented in 1642 by Blaise Pascal
• Mechanical calculator that can perform addition and subtraction directly
• Multiplies and divides through repeated addition and subtraction.

Tabulating Machine

• Designed by Herman Hollerith in 1890
• Summarizes data stored on punched cards
• Considered a step towards programming

Analytical Engine

• It was invented in 1834 by Charles Babbage
• It can input, process store and display output
• Basis of modern computers

Turing Machine

• It was developed in 1937
• General-purpose programmable machine
• Solves problems by executing programs stored on punched cards.

EDVAC/ENIAC

• In 1945, John Von Neumann introduced the concept of stored program computer
• This computer was capable of storing data and programs in memory

Transistor

• Developed at Bell Labs in 1947
• Replaced vacuum tubes
• Made using semiconductor materials

Integrated Circuit (IC)

• A silicon chip containing an entire electronic circuit
• Reduced the size of computers

Von Neumann Architecture

• The Von Neumann architecture consists of a CPU for processing, memory for storage, input/output devices and communication channels
• The Electronic Numerical Integrator and Computer (ENIAC) is the first binary programmable computer based on Von Neumann architecture
• Large Scale Integration (LSI) of electronic circuits allowed CPU integration on a single chip (microprocessor) during the 1970s
• Moore's Law predicted exponential growth in the number of transistors on a microchip
• Very Large Scale Integration (VLSI) in the 1980s integrated around 3 million components on a small chip
• Super Large Scale Integration (SLSI) fabricated around 106 components on a single IC
• IBM introduced its first personal computer (PC) in 1981, followed by Apple's Macintosh in 1984
• The Graphical User Interface (GUI) made computers more user-friendly, replacing command-line interfaces
• The World Wide Web (WWW) accelerated computer usage in the 1990s
• Laptops, smartphones, tablets, and personal digital assistants made computing portable
• These advancements were made possible through processor miniaturization, faster memory, and high-speed data and connectivity
• Wearable gadgets like smart watches, lenses, headbands, and smart appliances are the next wave of computing, leveraging IoT and AI

Computer Memory

• Computer systems need memory to store data and instructions for processing
• Primary memory, is the main memory
• Secondary memory stores data, instructions, and results permanently

Units of Memory

• Binary digits (0 and 1) are the basic units of memory, called bits
• Bits are grouped to form words
• 4-bit word = Nibble
• 8-bit word = Byte
• Bytes are grouped to make bigger chunks or units of memory

Types of Computer Memory

Primary Memory

• Essential component
• Programs and data are loaded before processing
• The CPU interacts directly with primary memory
• Two types of primary memory: Random Access Memory (RAM) and Read Only Memory (ROM)

RAM

• Volatile memory (data is lost when power is off)
• Used for temporary data storage while the computer is working
• Called 'main memory'
• It is faster than secondary memory

ROM

• Non-volatile memory (contents are not lost when power is off)
• Used for permanent storage of rarely changed content, like the startup program (boot loader)

Cache Memory

• High-speed memory between the CPU and primary memory
• Stores copies of frequently accessed data
• Reduces the average time to access data

Secondary Memory

• It has limited storage capacity, and is either volatile (RAM) or read-only (ROM)
• Auxiliary memory to store data or instruction permanently
• Non-volatile with larger storage capacity than primary memory
• Slower and cheaper than main memory
• Cannot be accessed directly by the CPU
• Needs to be brought the cpu to access
• Examples: Hard Disk Drive (HDD), CD/DVD, Memory Card
• Solid State Drives (SSD) has faster data transfer speeds
• Portable flash drives are used to transfer data between computers easily.

Data transfer

• Happens between the CPU, primary memory, and secondary memory
• Data is transferred using physical wires called a bus.
• Types of buses:
  • Data bus: Transfers data between components
  • Address bus: Transfers memory addresses between CPU and main memory
  • Control bus: Communicates control signals between components
• Data bus is bidirectional, while control and address buses are unidirectional
• A memory controller manages data flow into and out of the computer's main memory

Microprocessors

• A CPU implemented on a single microchip
• Microprocessors carry out tasks involved in data processing and arithmetic operations
• Microprocessors are built over integrated circuits with small components like resistors, transistors and diodes
• They have evolved to increase processing capability, decreasing physical size and reduced cost
• They can process millions of instructions per millisecond

Microprocessor Specifications

• Word Size: Maximum number of bits a microprocessor can process at a time
  • Increased from 8 bits to 16 bits to 64 bits
• Memory Size: Size of RAM varies depending on word size
  • Initially, small for 4/8 bits words, has become feasible to use RAM of sizes up to 16 Exabytes (EB) with 64 bit words
• Clock Speed: Number of pulses generated per second by the clock
  • Measured in Hertz (Hz), Kilohertz (kHz), and now Gigahertz (GHz)
• Cores: Basic computation unit of the CPU
  • Multi-core processors allows a computer to execute multiple tasks
  • CPUs with two cores (dual-core), four cores (quad-core), and eight cores (octa-core)

Microcontrollers

• Small computing devices that are embedded into another item
• Consist of a CPU, RAM, ROM, embedded on a single chip
• Designed for specific tasks
• Low cost
• Microcontrollers are used in washing machines, digital cameras, etc

Data and Information

• Computers use data and information
• Data is a broad term for any data

Data Types

• Raw, unorganized facts that are processed to get meaningful information
• Three types of data:
  • Structured data: data organized in a strict record structure (tables)
  • Unstructured data: data not organized in a pre-defined format (audio, video, graphics, tweets)
  • Semi-structured data: Not well defined, has internal tags or markup to define elements (CSV files)

Data Management

• Consists of capturing and organizing data
• Steps include:
  • Capturing: Gathering date from differenct sources
  • Storage: Storing data (can be challenging)
  • Retrieval: Fetching data from the storage device
  • Deletion and Recorvery: Process of deleting data, but also having backups to recover if data is lost

Software

• Computer hardware can't function on it's own; software is a set of instructions to operate hardware
• Instructions and data to be processed using computer hardware

Software Comprises

• A set of instructions which on execution deliver the desired outcome.
• Each piece of software is written for the purpose of a computation.
• Examples include Ubuntu or Windows 7/10, word processing tool like LibreOffice or Microsoft Word, video player like VLC Player, photo editors like GIMP and LibreOffice

Software need

• To make the computer operational
• Interacts with the end user
• Is an interface btw humans and hardware

Categorization of software

• System software
• Programming tools
• Application software

System Software

• Provides basic functionality to operate
• It knows how to operate different components
• Provides services to end users

Examples os System Softare

• Operating systems
• System utilities
• Device drivers

Operating Systems

• Most basic system software, other software doesn't work without it
• Manages application programs
• Provides access and security to users
• Popular Operating Systems:*
• Windows
• Linux
• Macintosh
• Ubuntu
• Fedora
• Android
• IOS

System Utilities

• Used for configuration and maintenance
• Some utilities ship with the OS (disk defragmentation tool, formatting utility)
• Others improve performance (anti-virus software)

Device Drivers

• Ensure proper function of a device
• Operating system work with the device

Programming tools

• Needed to give instructions, which give the desired outcome
• Computer languages assist to write instructions

Progrmaming Languages

• Translators need to convert to Machine

How to progrom

• Code editors are needed
• Human and Computers have separate needs to understand

Classification of Programing Languages

• Low level languages that are machine deopendent
• High level languages that easier to read

Language Translator

• Computer understands only machine language. A translator converts program written in assembly or a high-level language to machine
• Program code written using high-level language = Source Code
• *Assembler translator: * Converts Assembly Language to Machine Language
• Compiler translates the source into machine code
• *Interpreter *: Translates line by line

Program Development Tools

• Integrated Development Environment (IDE) has text editor, building tools, and a debugger

Application Software

• Designed to meet the needs of specific end-users
• Two Categories: General purpose application software and Customised appllication software

General Purpose

• Caters to a big audience
• For example, spreadsheet tool Calc of LibreOffice, Adobe Photoshop, GIMP, Mozilla web browser, iTunes,

Customised

• Tailor made that
• Can be a website, a software management system

Proprietary or Free and Open Source Software

• Free and Open Source Software (FOSS) developers provide source code
• Source code can be freely to those who want to improve the software by adding to it
• (FOSS) includes Ubuntu, Python, Libreoffice, Openoffice, Mozilla Firefox, etc.

Operating System

• Manage resources
• Manage hardware and device drivers
• Support for System Security
• Supports different users
• Windows is most important system software
• Linux, Android, Windows, Mac are other common system software

Objectibe for Operators

• provide services for building and running applications
• To provide user with commands or imputs for an operations

OS User Interface

• Each type provide different functionality
• Some commonly used interfaces are Command-based interface, Graphical User Interface, Touch-based Interface, and Gesture-based Interface

Types of UI

• • Command-based Interface. User has to do the command to perform task.
• • Graphical User Interface: GUI lets users run programs of icons ,menus ,etc
  • • Touch based, use the touch inputs ( used in touch screen)
  • • Audio use iOS to listen to user
  • • Gesture some phones let users interac by waving tilting etc

Functions of Operating System

• Process Management while operational a program is intended to carry many task
• As an opersting system that is a function, task is known as process
  • • Task are executed by CPU which is the primary computer system

Memory Management

• Primary or main memory of a computer system are usually limited to
• Task us to give (allocate) and take (free) memory from running processes.
  • • Should do it so it doesnt effect processing (so its faster)

File Management

• Data and programs are stored as files in the secondary storage of a computer system.
  • • File management are the data it stores (crucial to protection)
• Device management - A computer system has many I/O device, operating managment system work through them

This quiz covers fundamental concepts of computer architecture, including memory types, data transfer, bus systems, and RAM utilization. It explores the characteristics of primary and secondary memory, the roles of address, data, and control buses, and how RAM is used in executing applications.