Hardware and Software Systems Study Guide

Hardware and Internal Components

  • Hardware Definition: Hardware refers to the physical components of a computer system. Hardware is categorized into two types:

    • Internal Hardware: Components located inside the computer casing.
    • External Hardware: Peripheral devices connected to the computer from the outside.

  • Key Internal Hardware Devices:

    • Motherboard: This is a printed circuit board that serves as the foundation of the computer. It allows the Central Processing Unit (CPU) and all other hardware components to communicate with one another.
    • Central Processing Unit (CPU) / Processor: This is an electronic circuit board responsible for executing all instructions from a computer program. It is now commonly referred to as a single integrated circuit called a microprocessor. The CPU consists of two primary components:
      • Arithmetic Logic Unit (ALU): The part of the CPU where all arithmetic and logic operations are performed.
      • Control Unit (CU): This unit takes instructions, decodes them, and then executes the necessary operations.
    • Random Access Memory (RAM): An internal chip used to store memory temporarily while the system is operational. Information can be both read from and written to RAM. It is classified as volatile memory because data is lost when the computer is turned off.
    • Read Only Memory (ROM): Memory used to store data permanently. Information in ROM can only be read; it cannot be altered or edited. It is classified as non-volatile memory because data does not disappear when power is switched off.
    • Graphic Card: This component enables the computer to send graphical information to a video display device, such as a monitor or television. It is comprised of a processing unit, a memory unit, a cooling mechanism, and a connection display unit.
    • Sound Card: A circuit board that provides the computer with the ability to produce sound, record sound, and manipulate sound data stored on the hard disk.
    • Network Interface Card (NIC): This allows a computer to connect to the internet. NICs can be wired or wireless, and each card is hard-coded with a unique Media Access Control (MAC) address.
    • Hard Disk Drive (HDD) / Solid State Drive (SSD): These serve as one of the primary methods for storing data, files, application software, and system software.

  • BIOS and CMOS Functions:

    • ROM contains coding known as a boot file. This code instructs the computer on what to do immediately after being turned on. This is often referred to as the Basic Input/Output System (BIOS).
    • When the system is powered on, the BIOS checks if all devices are present and functional before rebooting the operating system.
    • The BIOS stores data in a non-volatile chip known as the Complementary Metal Oxide Semiconductor (CMOS).

Software Definitions and Classifications

  • Software Definition: Software consists of the instructions that control the computer system and process data. It is divided into two main categories: System Software and Application Software.

  • System Software: This software provides the platform upon which other software can operate. Its functions include:

    • Compilers: These convert programs written in high-level languages into machine code.
    • Linkers: These combine one or more object files produced by a compiler into a single file that can be executed on a computer.
    • Device Drivers: These allow one or more hardware devices to communicate with the operating system.
    • Operating System (OS): The OS enables users to communicate with the computer, allows input/output operations, handles errors, and manages system security.
    • Utilities: These help to manage, maintain, and control computer resources. Examples include antivirus software, disk repair tools, security features, screen savers, and file management tools.

  • Application Software: This software provides specific services requested by the user to solve given tasks. Examples and their functions include:

    • Word Processing: Used to manipulate text documents.
    • Spreadsheet: Used to organize and manipulate numerical data and text.
    • Database: Used to organize, manipulate, and analyze structured data.
    • Control and Measurement Software: Allows computers or microprocessors to interface with sensors to measure physical quantities and control specific applications.
    • Graphic Editing: Allows for the modification of bitmaps and vector images.
    • Video Editing: Enables users to manipulate video files to produce new videos.
    • Audio Editing: Allows users to edit, manipulate, and generate audio data.
    • Computer-Aided Design (CAD): Assists in the creation, modification, analysis, and manipulation of drawings or designs, producing 2D or 3D diagrams.
    • Apps and Applets: Applets are small applications designed to perform a single specific task on a device. Apps are software programs that can be downloaded through an app store and are capable of performing substantial tasks.

Data Representation and Conversion

  • Analogue Data: This is data understood by humans, consisting of real-world physical quantities or words.

  • Digital Data: This is the language understood by computers, typically represented in a binary format.

  • Analogue to Digital Converter (ADC): When a user enters a command into the computer, the ADC converts the human-readable text into binary format. This conversion allows the computer to understand the data and execute the command.

Input and Output Devices

  • Input Devices: These are hardware devices that allow a user to enter data or instructions directly into a computer. They are necessary for receiving commands and data for processing.

    • They send information to another device to carry out a specific function.
    • They are relatively complicated because they must ensure direct and correct contact between the user and the computer.

  • Output Devices: These devices take the output generated by the computer and convert it into human-readable language or use it to control another device.

    • They can receive signals from the computer but cannot send signals back to it.
    • They are necessary so that the user can understand the results provided by the computer.
    • They are generally less complex than input devices because their primary role is changing computer output back into analogue data.

Backing Storage and Memory Comparison

  • Backing Storage Characteristics:

    • Main forms include Hard Disk Drives (HDDs) and Solid State Drives (SSDs).
    • These devices store data permanently and can be either fixed or removable.
    • Storage capacity is considerably larger than that of RAM or ROM.
    • The cost per byte is cheaper than RAM or ROM.

  • Operational Differences:

    • Backing storage has much slower access times compared to RAM and ROM.
    • Unlike RAM/ROM, backing storage does not have direct contact with the CPU.
    • For the CPU to read data originating from backing storage, it must be stored in the computer's memory first.

  • Comparison Summary:

    • Internal Memory (RAM/ROM): High speed, low capacity, high cost per byte, direct CPU contact.
    • Backing Storage (HDD/SSD): Slow speed, high capacity, low cost per byte, no direct CPU contact.