DAN - Computer Components (Lesson)

Computer Components

Introduction

Before you can determine how to secure something, you must know how it works, right? For example, if you want to secure the door, you need to know how the lock works. In this unit, we will investigate the key components that make a computer and how these components work together to process data. Once we know how it works, we can begin to explore how things can go wrong and how to prevent data theft.

Computer Architecture Video

Necessary vs Optional Components Learning Activity

Click "Submit" in the bottom right corner of the activity when you are ready to submit your choices.

Image containing a digital camera, printer, computer monitor, tablet, laptop, cell phone, and computer mouse

Note that the term computing device spans many more types than those pictured in the graphic.  The list includes routers, “smart” home devices like thermostats or Ring doorbells, automobiles, robots . . . the list goes on and on.

This lesson will focus on Input, Memory, CPU, and Output but will not address power supply and motherboard.  Even though these are integral, it is assumed that power exists to supply electricity and a motherboard (aka circuit board) exists to hold components and provide pathways to conduct electrical signals.

Input

  • Input is any information or data sent to a computer or electronic device.
  • This can include actions like pressing a key on a keyboard, moving a mouse, touching a screen, or sending data through a network to a computer program. That is how data gets in!
  • User input can be keyboard, mouse, voice, touch, motion (video recording and/or lights), temperature (thermostat), etc. Attached devices can be  printers, network interface cards, modems, webcams, microphones, etc.

Storage/Memory

  • Temporary storage, commonly referred to as Random Access Memory (RAM), is a type of computer memory that is used to store data temporarily while a computer is running.
  • RAM is volatile, meaning that it loses its contents when the power is turned off.
  • This is in contrast to permanent storage, such as hard drives or solid-state drives, which retain data even when the computer is powered down.
  • RAM is called "random access" because any byte of memory can be accessed directly and almost instantly, without having to go through the bytes before it.
  • This makes RAM extremely fast and suitable for tasks that require quick access to data, such as running applications and processing tasks within an operating system.
  • The main function of RAM in a computer system is to provide quick read and write access to a storage medium that is much faster than hard drives or solid-state drives.
  • Operating systems and applications use RAM to store and access data and instructions that are being used or will be used imminently, allowing for efficient data processing and multitasking.
  • Types of storage can be flash/USB drives, hard drives, cloud storage, etc.

Processing/CPU

  • A CPU, or Central Processing Unit, is the primary component of a computer that performs most of the processing inside a computer.
  • Often referred to as the "brain" of the computer, the CPU interprets and executes the majority of the commands from the computer's other hardware and software.
  • All types of devices that utilize some form of computing, such as desktop computers, laptops, tablets, and smartphones, contain a CPU.
  • The CPU performs basic arithmetic, logic, control, and input/output (I/O) operations specified by the instructions in the program.
  • This process involves fetching the instruction from memory, decoding what the instruction does, executing the instruction, and then moving to the next instruction in a cycle known as the fetch-decode-execute cycle or the instruction cycle.
  • Modern CPUs are typically microprocessors, meaning they are contained on a single integrated circuit chip.
  • Each CPU has a set number of cores, with each core capable of performing its own tasks.
  • With advancements in technology, CPUs have become more powerful by increasing the number of cores (multicore processors), enhancing the clock speed, and improving efficiency in executing more instructions per cycle.

Output

  • The output of a computer refers to the data and information that are produced and delivered to the user or to another system after processing.
  • The output can take various forms, depending on the nature of the task and the output devices connected to the computer. Common types of computer outputs include:
    1. Visual Display: Information displayed on a screen, such as text, graphics, and videos, typically via a monitor or projector. This is the most common form of computer output, used for everything from basic computing tasks to complex graphical presentations.
    2. Printed Material: Documents, photographs, and other items printed on paper or other substrates by a printer. This includes everything from simple text documents to high-quality photographic prints.
    3. Audio: Sound output, including music, speech, and other sounds, played through speakers or headphones. This can range from simple beeps and system alerts to complex compositions played by digital audio workstations.
    4. Digital Data: Output doesn't always have to be human-readable or perceptible. Computers can output data in digital form to be stored on storage devices or transmitted over networks. This includes saving files to a hard drive, sending an email, or uploading content to the Internet.
    5. Physical Movement or Actions: In specialized systems like robotic controllers or embedded systems, the output can be physical actions. For instance, a computer-controlled robotic arm might move or assemble parts in response to computer commands.
    6. Multimedia and Virtual Reality: Outputs that combine several types of media, such as video, audio, and interactive elements, are common in gaming and virtual reality applications. This might involve specialized output devices like VR headsets.
    7. Tactile Output: Devices like braille displays provide tactile output for visually impaired users, converting text to a form that can be felt with the fingers.
  • The nature of a computer's output is determined by the software application in use and the output devices available.
  • Over time, as technology advances, new forms of output continue to emerge, enhancing the ways in which computers can communicate information.

Computer Components, Cybersecurity, and What Can Go Wrong

Reflection and Wrap-up

In this lesson, you have learned about the critical and optional components of a computer, including the central role played by the CPU, RAM, power supply, and motherboard. You've also been introduced to various cybersecurity threats that can target these components, such as wireless keyboard sniffers, Cold Boot attacks, and CPU vulnerabilities like Spectre, Meltdown, and Foreshadow. Additionally, you've explored how outputs like computer monitors can be compromised through attacks like Monitor Darkly, emphasizing the importance of understanding both hardware functions and potential security risks.

[CC BY-NC-SA 4.0 Links to an external site.] UNLESS OTHERWISE NOTED | IMAGES: LICENSED AND USED ACCORDING TO TERMS OF SUBSCRIPTION - INTENDED ONLY FOR USE WITHIN LESSON. Video courtesy of KarBytes CS, CC-BY.