History of Computing and Early Machines

Computer Architecture & OS - Unit 1

• Definition of Computer: A device that assists in performing calculations, from prehistorical counting tools to modern computers.

• Tally Sticks: Used between 35,000 BCE and 20,000 BCE to record quantities, not for calculations. Belonged to the prehistorical counting tools.

• Abacus: A counting frame used since 1700 BCE; still in use; used for basic arithmetic calculations, including square and cubic roots.

• Pascal Calculator: A shoebox-sized calculator that could add, subtract, multiply, and divide, operating with up to six digits. Mechanical method for performing calculations.

• Stepped Reckoner: A mechanical calculator that could handle multiplication of eight-digit numbers, division of 16-by-8 digit numbers, and addition/subtraction.

• Jacquard Loom: A mechanical device that used punched cards for programming, considered a precursor to punched card computers.

• Babbage Machine: A series of mechanical calculators, including the Difference Engine, designed to automate complex mathematical calculations. Emphasized accuracy and minimized errors in calculations.

• Turing Machine: A theoretical model that became a foundation for modern computers; consists of a read/write head, a tape, and a state table. Used as an abstract concept for describing computation.

• ENIAC: A numerical integrator and calculator, the grandfather of digital computers that used vacuum tubes in its design. Consuming 150 kWh and able to multiply ten-digit numbers.

• Modern Computers: Advanced technologies like transistors replaced vacuum tubes, leading to smaller, more efficient devices. Development of common business language (COBOL) as the first programming language.

Computer Architecture & OS - Unit 1.2

• Decimal System: A base-10 system using symbols 0-9 to represent numbers.

• Binary System: A base-2 system using only 0 and 1; fundamental for computer operation. These symbols represent the electrical "on" (1) or "off" (0) states.

• Decimal to Binary Conversion: Repeatedly dividing the decimal number by 2 and recording the remainders (read in reverse order).

• Binary Addition: Numbers are added bit by bit, carrying over where needed.

• Hexadecimal System: A base-16 system using 0-9 and A-F to represent numbers. Handy for representing binary data in a more concise form.

• Hexadecimal to Decimal Conversion: Similar to decimal to binary, uses place values based on powers of 16.

• Decimal to Hexadecimal Conversion: Repeated division by 16 and recording remainders (read in reverse order).

• Logic Gates: Fundamental building blocks in digital electronics. Key gates like NOT, AND, OR, NAND, NOR, and XOR.

Computer Architecture & OS - Unit 1.3

• Semiconductor Materials: Materials with electrical conductivity between conductors and insulators; used in transistors. Most common: Silicon and Germanium.

• Transistors: Electrical switches controlled by voltage, allowing the ON (1) or OFF (0) states, fundamental for modern computers. Consists of three terminals: gate, source, and drain.

• MOSFETs: Metal-oxide-semiconductor field-effect transistors, most commonly used transistors in computer chips. Two main types: nMOS and pMOS.

• nMOS: When the gate is "1", there is a connection between the source and drain. "0" = no connection = OFF.

• pMOS: When the gate is "0", there is connection between the source and drain. "1" = no connection = OFF.

Computer Architecture & OS - Unit 1.4

• Digital Circuits: Use discrete signals (on/off voltages) to perform logical operations. Includes logic gates that determine output from bit inputs. The fundamental blocks to any electronic device, including computers.

• Combinational Circuits: Outputs depend only on the current input values, meaning current input values are used to compute the output values.

• Sequential Circuits: Outputs depend on current and previous input values. Memory-like characteristics. The outputs rely on the sequence of inputs, and the previous states are stored in bits known as "state variables".

• Digital Adders: Circuits that execute addition operations.

• Full Adder Logic Circuit: Example of circuitry that employs logic gates for addition.

Computer Architecture & OS - Unit 2

• Computer System Architecture: How the computer's components are organized, including physical aspects and communication between parts.

• Computer System Organization: A description of the arrangement of the internal components and how these parts of the computer system interact to complete a given task.

• Von Neumann Architecture: An architectural style where data and instructions are stored in the same memory space. Data and instruction share the same memory→ use a single memory bus.

• CPU Components: Includes ALU (Arithmetic Logic Unit), Control Unit, and Registers.

• ALU: Performs arithmetic and logical operations.

• Control Unit: Manages and controls the execution of instructions; coordinates process actions.

• Registers: Small, high-speed storage locations inside the CPU. Data from memory has to be transferred into registers inside the CPU to be used for operations.

• Memory: Stores data and instructions.

• I/O Devices: Devices for transferring data to and from the computer.

• Bus Systems: Used as a communication pathway between components like CPU, memory, and I/O devices.

Computer Architecture & OS - Unit 2.2

• Instruction Set Architecture (ISA): The logical view of a computer system's capabilities, providing an interface for software interaction.

• Assembly Language : Human-readable representation of machine instructions, using symbols for machine-executable instructions (ex. "add"). For easier understanding by programmers.

• Machine Language: The binary code that directly controls the computer hardware.

• Addressing Mode: The method for specifying the location of operands or data.

• R-Type Instructions: Operate on registers; typically use three register operands.

• I-Type Instructions: Operate on registers; typically include an immediate value as well.

• J-Type Instructions: Indicate jumps or branches. Primarily used for controlling the flow of execution.

Computer Architecture & OS - Unit 3

• Personal Computers (PC): Digital computers designed mainly for single users, with a central processing unit (CPU), memory, and I/O devices.

• Transistors: A switch controlled by voltage; replaced vacuum tubes to make PCs smaller and faster.

• Magnetic Core Memory: Common RAM technology in 1960s to 1980s. Using magnetic hysteresis for storing data.

• Microprocessors: Integrated circuits that contain CPUs, the heart of PCs.

• Mainframes: High-performance computer systems designed for large-scale data processing, typically used in businesses for complex tasks.

• Supercomputers: The fastest and most powerful computers available, frequently employing parallel processing to perform complex calculations quickly.

• Mobile Systems: Portable computers, including laptops, tablets, and mobile phones, designed to offer easy access to information and computing power.

Computer Architecture & OS - Unit 4

• Assembly Language: A set of instructions using symbolic names instead of binary code, easier for programmers to read and write.

• Compilation of source code: A series of steps:

  • Preprocessing
  • Compilation
  • Assembling
  • Linking

• The linker: Connects objects (containing codes) of different modules.

Computer Architecture & OS - Unit 5

• Operating Systems (OS): Software that manages computer hardware and software; provides an interface between users and computer hardware (ex, managing memory, CPU, or I/O devices).

• Kernel Mode: Operations that allow full access to hardware.

• User Mode: Restricted access to hardware, through specific instructions in OS.

• Monolithic Kernels: All OS functions in a single file. Larger and faster way to manage processes because the functions can interact without extra mechanisms.

• Microkernel Kernels: OS functions in separate modules; less memory consumption, but slower functions.

• Process: An instance of running program on the computer.

• Threads: A lightweight process with limited hardware needs which can run at the same time in parallel.

• Scheduler: Manages the execution order of processes (which executes first, when it blocks, ....).

• Memory Management: Managing RAM space allocation and use.

• File Systems: The organization of files on the hard disk. Includes File naming convention and File hierarchies.

• Protection Mechanism: Method to protect files and applications in the system.

Computer Architecture & OS - Unit 6

• Windows: A common operating system (OS) for personal computers.

• Other Operating Systems: Other common operating systems (OS) include macOS, Linux, and Unix. They vary in their architecture and design features. Note: The subheadings are based on the provided OCR and may not precisely reflect the section titles in the original document.

This quiz explores the history and evolution of early computing machines, including ENIAC, vacuum tubes, and the contributions of pioneers like Charles Babbage and Grace Hopper. It examines key concepts in programming, binary arithmetic, and the significant advancements that led to modern computing. Test your knowledge on the innovations that shaped the landscape of computer technology!