Computer Architecture: Key Concepts and Definitions

Computer Transmission Methods

  • Simplex: Single direction transmission.
  • Half-Duplex: Transmission in both directions, but not simultaneously.
  • Full-Duplex: Simultaneous transmission in both directions.

Main Memory Function

Stores programs and data.

Computer Structure

Mechanisms for information exchange between the CPU, main memory, and input/output devices.

Acronyms

  • REM: Address Bus
  • RDM: Data Bus
  • IR: Instruction Register
  • PC: Program Counter
  • ACC: Accumulator Register
  • UC: Control Unit
  • ULA: Arithmetic Logic Unit

Instruction Level Parallelism

Executing two or more operations at the same time.

Process Level Parallelism

Executing instructions on two or more processors simultaneously.

Multicomputers

A large number of interconnected computers without any shared memory.

Main Memory Access Methods

Sequential, Direct, Random, Associative.

RAM Classification

  • Static RAM (SRAM)
  • Dynamic RAM (DRAM)

Static RAM (SRAM)

Circuits built from basic D flip-flops.

Cache Memory

Small, fast memory located between the CPU and main memory.

Secondary Memory Types

  • Magnetic Disk
    • RAID (Redundant Array of Independent Disks)
    • Removable / Fixed
  • Optical Disk
    • CD-ROM

RAID (Disk)

Redundant Array of Independent Disks or Redundant Array of Inexpensive Disks.

Bus Arbitration

The chip that decides whether to use the bus when a process and an I/O controller want to use it.

Main Computer Features

An electronic machine composed of physical elements, capable of performing a variety of tasks with high speed and precision.

Major Areas of Informatics

  • Hardware: Equipment
  • Software: Programs
  • Peopleware: Users

Instructions from programs are executed in the CPU (Central Processing Unit).

Data travels through the computer: letters, numbers, images, and sound.

Memory Hierarchy

Ordered by decreasing speed and capacity: Registers, internal cache, external cache, RAM, and Hard Disk/auxiliary memory.

Definition of a Computer Language

The means of communication between humans and machines.

Definition of Cybernetics

The physical and logical means of communication between various sciences.

Definition of Artificial Intelligence

The ability of a machine to make or suggest decisions.

Machine Language Representation

Binary representation: 1 (on) contains information, and 0 (off) absent information.

Low-Level Language

The language closest to the machine, e.g., Assembly.

High-Level Language

A language that can theoretically be executed on any machine, such as C, Fortran, or Java, whose instructions are composed of words in English.

Assembly Language

A symbolic language that can be easily translated into machine language.

Computer Generations

  • Zero Generation (1642-1945): Mechanical computers
  • 1st Generation (1946-1952): Vacuum tube computers
  • 2nd Generation (1955-1965): Transistor computers
  • 3rd Generation (1965-1980): Integrated circuit computers
  • 4th Generation (1980-1990): VLSI computers

Data Processing Rules

  • Batch: Batch processing.
  • On-Line: Processing linked to a Central Control Unit (Server).
  • Real-Time: Processing executed in real-time (Direct).

Computer Structure

  • Physical (Hardware) = Equipment
  • Logic (Software) = Programs
  • Interconnection = Link

Input/Output Devices

  • Communication between the user and the computer.
  • Communication between the computer and the environment (external devices such as monitors or controlled devices).
  • Data storage (recording).

Computer Input Devices

Keyboard, mouse, scanners, barcode readers, magnetic card readers, video cameras, microphones, sensors, transducers, etc.

Computer Output Devices

Printers, video monitors, plotters, actuators, switches, etc.

Input/Output Devices

Storage: Disks, tapes.