CO (copy)

Structure of Coms

ComponentComputer Types: Different classifications of computers based on functionality.

  • Functional Units: Essential units responsible for operations (ALU, Control Unit, etc.).

  • Basic Operational Concepts: Principles governing computer operations.

Architectures

  • Von‐Neumann Architecture: The standard architecture model which includes a processing unit, memory, and input/output mechanisms.

  • Bus Structures: Communication pathways that connect different components in a computer.

  • Performance: Measures assessing the effectiveness of computer systems.

  • Multiprocessors and Multicomputers: Systems designed for simultaneous processing.

Data Representation

Numeric Data Types

  • Fixed and Floating Point: Different formats for representing numerical data.

  • Error Detecting Codes: Methods to check for errors in data transmission.

Register Transfer and Micro-Operations

Concepts

  • Register Transfer Language: A set of commands to facilitate data transfer between registers.

  • Micro-Operations: Basic operations that can be performed on the data in registers.

  • Arithmetic Micro-Operations: Perform basic arithmetic operations on data stored in registers.

  • Logic Micro-Operations: Perform logical operations (AND, OR, NOT) on data.

  • Shift Micro-Operations: Operations that shift the bits of a register left or right.

Computer Architecture vs. Organization

Definitions

  • Computer Architecture: Abstract design specifying the functionality of a computer system.

  • Computer Organization: Realization of architecture focusing on operational aspects like control signals and hardware setup.

Generations of Computers

Overview

  • First Generation (1946-1959): Vacuum tube technology; unreliable and costly.

  • Second Generation (1959-1965): Introduction of transistors; more reliable and cheaper.

  • Third Generation (1965-1971): Integrated circuits; reduced size and cost, increased reliability.

  • Fourth Generation (1971-1980): Very large scale integration, personal computers emerged.

  • Fifth Generation (1980-present): Focus on artificial intelligence and advanced processing technologies.

Characteristics of First Generation Computers

  • Components: Vacuum tubes; slow and bulky.

  • Operations: Batch processing; only machine language supported.

  • Examples: ENIAC, UNIVAC.

Second Generation Features

  • Components: Transistors; more efficient and cheaper than vacuum tubes.

  • Language: Assembly language and early high-level programming languages (e.g., Fortran).

  • Examples: IBM 7094.

Third Generation Features

  • Components: Integrated Circuits; reduced costs dramatically.

  • Language: High-level programming languages became more prevalent.

  • Examples: IBM-360 series.

Fourth Generation Features

  • Components: VLSI chips lead to the emergence of personal computers.

  • Technologies: Introduction of the Internet and networking technologies.

  • Examples: CRAY computers.

Fifth Generation Features

  • Components: ULSI technology enabling tiny, powerful circuits.

  • Focus: Artificial intelligence and parallel processing capabilities.

  • Examples: Desktop, laptop computers with advanced interfaces.

Types of Computers

Based on Operating Principles

  1. Digital Computers: Handle discrete data (0s and 1s).

  2. Analog Computers: Use continuous data for operations.

  3. Hybrid Computers: Combine characteristics of both types.

Classification by Size and Capability

  • Microcomputers: Smallest general-purpose computers (e.g., personal computers).

  • Minicomputers: Mid-range systems, more powerful than microcomputers.

  • Mainframes: Large systems capable of handling extensive tasks simultaneously.

  • Supercomputers: Extremely high-speed machines designed for complex calculations.

Memory Organization

Concepts

  • Types of RAM and ROM: Different memory technologies used for storage.

  • Cache Memory: High-speed storage that improves access times.

  • Secondary Storage: Hard drives and other long-term storage solutions.

RAID and DMA

RAID Levels

  • RAID 0: Improves performance via data striping without redundancy.

  • RAID 1: Mirrors data for reliability.

  • RAID 5/6: Offers fault tolerance and is appropriate for important data storage.

Direct Memory Access (DMA)

  • Function: Allows peripherals to communicate with memory directly, freeing CPU resources.

  • Benefits: Increases efficiency by minimizing CPU overhead during data transfers.

Instruction Formats

Types

  1. Single Accumulator Organization: Basic operations performed using a single accumulator.

  2. General Register Organization: Involves multiple registers for operations.

  3. Stack Organization: Uses stack for storing operations temporarily.

Addressing Modes

  1. Immediate: Operand is directly within the instruction.

  2. Direct: Address of the operand is specified explicitly.

  3. Indirect: Address is held in a register or memory location.

  4. Register: Uses a register to hold the operand.

  5. Displacement: Combines a direct address with a register.

  6. Stack: Operands are taken from the stack.

Fetch-Execute Cycle

Steps

  • Fetch: Instruction is fetched from memory, stored in the Instruction Register.

  • Decode: Instruction is decoded to determine required operation.

  • Execute: ALU performs the operation and results are processed.

Error Detection and Correction

Techniques

  • Use parity bits, checksums, and other encoding methods to verify data integrity during transmission.