Computer Basics Notes

1. What is the difference between ROM and RAM?

  • ROM (Read-Only Memory): Non-volatile memory that stores essential instructions for booting the computer and performing basic functions. It retains data even when the computer is turned off.

  • RAM (Random Access Memory): Volatile memory that temporarily stores data and programs the CPU needs while the computer is running. It loses its data when the computer is powered off.


    2. How does RAM affect a computer’s performance?

    More RAM allows a computer to handle more programs simultaneously and run them efficiently. Insufficient RAM causes slow performance, as the system has to rely on slower storage (like the hard drive) for data it can’t keep in RAM.


    3. How many Bytes in a Gigabyte? in a Kilobyte?

    • 1 Gigabyte (GB) = 1,024 Megabytes (MB) = 1,073,741,824 Bytes (1 GB = 2³⁰ bytes).

    • 1 Kilobyte (KB) = 1,024 Bytes (1 KB = 2¹⁰ bytes).


    • 4. List from smallest to largest: kilobyte, megabyte, byte, bit, terabyte, gigabyte

      Bit → Byte → Kilobyte (KB) → Megabyte (MB) → Gigabyte (GB) → Terabyte (TB)
      5. Alice has 600 MB of data. Bob has 2000 MB of data. Will it all fit on Alice's 4 GB thumb drive? (from
      Stanford article)

      Alice has 600 MB, and Bob has 2,000 MB of data.
      Combined: 600 MB + 2,000 MB = 2,600 MB.
      Since 4 GB = 4,096 MB, Alice's 4 GB thumb drive has enough space to store both sets of data (2,600 MB < 4,096 MB).


      6. Alice has 200 small images, each of which is 600 KB. How much space do they take up overall in MB?

      200 images × 600 KB = 120,000 KB.
      120,000 KB ÷ 1,024 = 117.19 MB.
      So, the images take up approximately 117.19 MB of space.
      7. How is data represented in a computer?

      Data is represented in a computer as binary code, using sequences of bits (0s and 1s). Each bit represents a state (on/off), and combinations of bits represent more complex data like numbers, characters, or instructions.


      8. What is the job of the Operating System? List 3 Operating Systems.

      The operating system (OS) manages hardware and software resources, provides a user interface, and ensures tasks and processes are executed smoothly.

    • windows, macOS, Linux
      9. When we refer to an operating system, are we referring to hardware or software?

    • The operating system is software.
      10. List from most general (most abstract) to most specific (least abstract): USB flash drive, byte, secondary storage.

    • Secondary Storage → USB Flash Drive → Byte
      11. List from most general (most abstract) to most specific (least abstract): Microsoft Office, Software,Excel.

    • Software → Microsoft Office → Excel
      12. Briefly explain each of the Technical Specifications of the MacBook Pro listed below.
      a. 12-core CPU with 8 performance cores and 4 efficiency cores

    • The CPU (Central Processing Unit) has 12 cores in total, divided into 8 performance cores for handling high-demand tasks like video editing or gaming, and 4 efficiency cores designed for less demanding tasks like web browsing to save power and improve battery life.
      b. 19-core GPU

    • The GPU (Graphics Processing Unit) has 19 cores, meaning it can handle more complex graphical tasks, which is especially useful for activities like video rendering, gaming, and 3D modeling.
      c. 16-core Neural Engine

    • The Neural Engine has 16 cores and is designed for tasks that involve machine learning, such as facial recognition, speech processing, and AI-based applications. It speeds up these tasks by handling them in parallel.
      d. 200GB/s memory bandwidth

    • This is the rate at which data can be transferred between the CPU/GPU and memory, with 200 gigabytes per second being very fast, allowing for smoother multitasking and better performance in demanding applications.
      e. 16GB unified memory

    • The unified memory architecture means that both the CPU and GPU share the same pool of 16GB RAM, which allows for faster data access and more efficient memory use compared to traditional systems where CPU and GPU have separate memory.
      f. 32MB L3 cache shared across all cores

    • The L3 cache is a type of memory that is faster than regular RAM but smaller in size. The 32MB cache is shared across all cores, improving the speed of data access for frequently used information, leading to better overall performance.
      g. 1TB SSD storage

    • This is the device’s storage capacity. 1TB (terabyte) SSD (Solid-State Drive) storage means it uses faster, more reliable technology than traditional hard drives (HDDs) for data storage and retrieval, resulting in quicker boot times and faster file access.
      h. Retina display

    • A high-resolution display where individual pixels are so small that they aren’t discernible to the naked eye at typical viewing distances, resulting in sharper text and images.
      i. 3 Thunderbolt 4 ports

    • Thunderbolt 4 is a high-speed interface that allows for data transfer, video output, and charging using a single port. Having three ports allows for multiple connections to peripherals like external displays, storage devices, or charging.
      j. HDMI port

    • An HDMI port allows the MacBook Pro to connect to external displays, projectors, or TVs using an HDMI cable, commonly used for video and audio transmission.
      k. Touch ID

    • A fingerprint sensor used for secure authentication, allowing you to log in, authorize purchases, and unlock your MacBook with a simple touch.
      13. What are the advantages of a multi-core processor?

    • Improved Performance: Multi-core processors can handle more tasks simultaneously, leading to faster performance, especially for multitasking or running complex software.

    • Power Efficiency: Dividing tasks between cores helps manage power consumption, particularly with a mix of performance and efficiency cores.

    • Better Parallel Processing: Many modern applications are optimized to take advantage of multiple cores, allowing for faster processing times.
      14. What is the difference between a modem and a router?

    • Modem: A modem connects your home to your Internet Service Provider (ISP) and converts the internet signal to a usable form (either digital or analog).

    • Router: A router distributes the internet connection from the modem to various devices in your home, either wirelessly (Wi-Fi) or via wired connections (Ethernet).
      15. List the following in device connection order of their connections to each other? Assume that the modem and router are two separate devices.
      Modem ISP Router Laptop computer Internet

    • ISP → Modem → Router → Laptop Computer → Internet
      16. What units are used to measure:
      a. RAM? How much would be a reasonable choice when purchasing a computer?

    • Measured in gigabytes (GB) or terabytes (TB).

    • A reasonable amount for most users would be 8GB to 16GB for general tasks and gaming, while professionals might require 32GB or more for video editing or software development.
      b. Hard Drive Capacity? How much would be a reasonable choice when purchasing a computer?

    • Measured in gigabytes (GB) or terabytes (TB).

    • A reasonable choice would be at least 512GB for light users, but 1TB or more is ideal for storing large amounts of data, like videos, photos, and programs.
      c. Processor Speed? What's good here?

    • Measured in gigahertz (GHz).

    • A good processor speed would be 2.5GHz to 4GHz for modern CPUs. A higher speed generally means faster performance.
      17. What is the difference between a hard disk drive (HDD) and a solid-state drive (SSD)?

    • HDD: Uses spinning disks and a mechanical arm to read/write data. It’s slower, noisier, and more susceptible to physical damage but typically offers more storage at a lower cost.

    • SSD: Uses flash memory with no moving parts, making it faster, quieter, more durable, and more energy-efficient, though more expensive per gigabyte than HDDs.
      18. How do you delete files from your computer? How are you sure that no one can access your deleted files (or any files)?

    • Deleting Files: Files can be deleted by moving them to the recycle bin (Windows) or trash (Mac) and then emptying it. Alternatively, files can be deleted directly using keyboard shortcuts.

    • Ensuring Files are Unrecoverable:

      • Use a file-shredding tool: These overwrite the data with random patterns to make recovery difficult.

      • Encrypt sensitive data before deletion to ensure even if recovered, it can't be read.

      • Factory reset your device or use specialized software for securely erasing entire drives to prevent recovery.

Blown to Bits Questions:

1. We accept our loss of privacy in exchange for what?

benefits of the digital world
2. What did the Snowden files contain?

a trove of classified documents and PowerPoint presentations describing massive U.S. government communications surveillance: a series of front-page stories for the journalists. They showed the NSA engaged in pervasive communications surveillance—not just of foreigners and suspected terrorists but of law-abiding American citizens.
3. What did the USA Patriot’s Act authorize?

national security letters, which are secret demands for communications records; warrantless wiretaps of foreigners suspected of terrorist activity; and increasing ability to collect information on citizens any time obtain- ing foreign intelligence information is “a significant purpose” of the sur- veillance
4. How does GPS function?

calculates locations based on the satellites’ locations and the times their signals are received. The 24 satellites spinning 12,500 miles above the earth enable your car to locate itself within 25 feet, at a price so low that most new cars have it as a standard feature. What was once a military secret now comes free in every smartphone.
5. What is an EDR? How can its information be used?

an event data recorder (EDR) that captured every detail about what was going on just before the crash. An EDR is an automotive “black box” like the ones recovered from airplane crashes. EDRs capture information about speed, braking time, turn signal sta- tus, seat belts: information needed for accident reconstruction, to establish responsibility, or to prove innocence.
6. Give one advantage and one disadvantage of an RFID-enabled device in your car.

The transponder, which the driver attaches to the windshield inside the car, is an RFID-enabled device powered with a battery that sends informa- tion to a sensor several feet away as the driver whizzes past. The sensor can be mounted in a constricted travel lane, where a toll booth for a human toll taker might have been. Or it can be mounted on a boom above traffic so the driver doesn’t even need to change lanes or slow down. And what is the possible harm? Of course, the state is recording the fact that the car has passed the sensor; that is how the proper account balance can be debited to pay the toll. When the balance gets too low, the driver’s credit card may get billed automatically to replenish the balance, which only makes the system better—no fumbling for change or doing anything else to pay for your travels.
7. What is meant by deidentified data?

To use the official lingo, the data was “deiden- tified”—that is, stripped of identifying information.
8. What is meant by IoT? Give 3 examples

IoT (Internet of Things) refers to a network of physical devices, vehicles, appliances, and other objects embedded with sensors, software, and connectivity features that enable them to collect and exchange data over the internet.

Nowhere is this principle more evident than in the networking of light switches, refrigerators, and doorbells known as the Internet of Things (IoT).