COMPSOR 1

Digital Computer

Fast electronic machine for processing digitized information.

Computer Program

List of instructions stored internally for processing.

Computer Memory

Internal storage for programs and data during execution.

Personal Computer

Common computer used in homes and offices.

Workstation

High-powered desktop computer for engineering applications.

Mainframe

Large computer for business data processing.

Supercomputer

Used for large-scale numerical calculations.

Input Unit

Accepts coded information from users or devices.

Examples of Input Devices

Keyboard, mouse, scanner, joystick, barcode reader.

Primary Storage

Fast memory where programs are executed.

Word Length

Number of bits processed as a single unit.

Memory Access Time

Time to access one word in memory.

Random-Access Memory (RAM)

Memory allowing access to any location quickly.

Secondary Storage

Used for storing large amounts of data.

Arithmetic and Logic Unit (ALU)

Executes most operations and contains registers.

Control Unit (CU)

Directs operations and sends control signals.

Central Processing Unit (CPU)

Combination of ALU and CU in a computer.

Output Unit

Sends processed results to external devices.

Von Neumann Architecture

Stored program architecture storing programs in memory.

Machine Language

Primitive language consisting of binary code.

Assembly Language

Uses mnemonics to simplify programming tasks.

Bottleneck

Limitation in performance, often in memory access.

Registers

High-speed storage for frequently used operands.

Control Signals

Commands sent by CU to coordinate operations.

Fixed Size Groups

Data processed in groups called words.

Addressing

Assigning distinct addresses to memory locations.

Examples of Output Devices

Monitors, printers, plotters, modems.

Mnemonic

Easy-to-remember abbreviations for programming.

Assembler

Translates assembly language to machine language.

High-Level Language

Uses English-like commands for programming.

Compiler

Translates high-level language to machine language.

FORTRAN

Formula translation programming language.

COBOL

Common business-oriented programming language.

BASIC

Beginner's all-purpose symbolic instruction code.

Pascal

High-level programming language for structured programming.

Compact Code

Machine language format for efficient execution.

Speed

Execution time related to code length.

Flexibility

Low-level languages allow programming freedom.

ADD Instruction

Adds operand from memory to a register.

Program Counter (PC)

Holds address of next instruction to execute.

Memory Address Register (MAR)

Holds address for data transfer in memory.

Memory Data Register (MDR)

Contains data to be read or written.

Instruction Register (IR)

Holds the current instruction being executed.

Bus

Collection of wires connecting computer devices.

Data Bus

Transmits data between devices.

Address Bus

Specifies data location in memory.

Control Bus

Manages control signals within the computer.

Fetch Cycle

Process of retrieving an instruction from memory.

Write Cycle

Process of sending data to memory.

Operand

Data used in an instruction operation.

ALU

Arithmetic Logic Unit for performing calculations.

Subroutine

Reusable code block for specific tasks.

Predefined Functions

Built-in functions simplifying programming tasks.

Single-Bus Structure

All units connect via one bus system.

Bus Control Lines

Arbitrate multiple requests for bus access.

Buffer Registers

Hold data during transfers to prevent delays.

Two-Bus Structure

Uses two buses for I/O and memory transfers.

Peripheral Processor

Controls I/O transfers in two-bus systems.

Memory Locations

Specific addresses where data is stored.

Address Space

Total memory addresses available in a system.

Intel 8088/86

Microprocessor with 1,048,576 addressable locations.

Store Cycle

Transfers data from CPU to memory, overwriting contents.

Data Transfer Instructions

Move data between memory and CPU registers.

Arithmetic Operations

Perform calculations on data in CPU.

Program Sequencing

Controls the order of instruction execution.

Three-Address Instructions

Specify two source operands and one destination.

Two-Address Instructions

Use one destination and one source operand.

One-Address Instructions

Assume one operand is in the accumulator.

Zero-Address Instructions

Operands are defined implicitly within the instruction.

Instruction Fetch

Retrieves instruction from memory to CPU.

Instruction Execute

CPU performs operation specified by instruction.

Straight-Line Sequencing

Executes instructions in increasing address order.

Branching

Repeats instruction sequences in program loops.

Accumulator

Register used for implicit operand storage.

I/O Operations

Manage input and output data transfers.

Operands

Data items used in operations or instructions.

Op-Code Field

Specifies the operation to be performed.

Addressing Information Field

Specifies addresses for operands in instructions.

Memory Management

Organizes and allocates memory for operations.

Data Representation

Memory contents can represent instructions or data.