Chapter 1 - Data Storage
General Outcomes
- Recognize that the fundamental building blocks of computers are logic gates and, given their inputs, be able to determine the output of a simple collection of gates.
- Apply an understanding of how computers represent various kinds of values to a variety of situations in both a CS classroom and daily life, e.g.,
- Explain bits and bytes and how they are organized.
- Explain how the same sequence of bits can be interpreted as different types of data (numbers, images, sound, text, etc.)
- Given an encoding type (base-ten, hexadecimal, or simple floating point), translate a bit-string into its corresponding value .
- Explain standard encodings for various forms of "media" (text, images, and sound).
- Estimate storage requirements for various forms of "media" based on size needed for representation and elements being represented (e.g., bits needed for individual values and the number of values needed).
- Justify the choice of a particular compression technique for a data file.
- Explain surprising or incorrect results from computer programs.
- Discuss situations where inexactness of computer calculations matter and don't matter explaining the source of the inexactness.
- Recognize that computers are not infallible—that errors can occur and can, in some cases, be recognized and corrected.
- Apply understanding of representation and storage knowledge to social issues, e.g.,
- Liability in various scenarios.
- Ethics of actions in various scenarios.
- Consequences of decisions in various scenarios.
Reading Guide
In order to guide your reading we have designated each section into one of three categories:
- Essential - You should thoroughly read this material and be prepared to answer questions about this material in both discussions and on assessments.
- Important - You should read this material and be prepared to participate in potential discussions/activities about this material. While this material will not be directly assessed, your understanding of this may help you support/improve your answers to "Essential" material.
- Useful - We feel that this material is worth knowing and may supplement other material in the chapter. However, we do not plan on assessing or discussing (unless you ask questions).
Section | Essential | Important | Useful |
---|---|---|---|
1.1 Bits and Their Storage | |||
Boolean Operations | |||
Gates | |||
Flip Flops | |||
Hexadecimal | |||
1.2 Main Memory | |||
1.3 Mass Storage | Addressed in Unit 2 | ||
1.4 Representing Information as Bit Patterns | |||
1.5 The Binary System | |||
1.6 Storing Integers | |||
Twos Complement | |||
Addition in Twos Complement | |||
The Problem of Overflow | |||
Excess Notation | |||
1.7 Storing Fractions | |||
1.8 Programming | |||
1.9 Compression | |||
1.10 Communication Errors | |||
Parity Bits | |||
Error Correcting Codes |
Video Resources
The following videos are used in individual lessons during the study of this chapter. Their links are consolidated here for quick reference.- Crash Course Computing (Preview): Introduction
- Crash Course Computing #1: Early Computing
- Crash Course Computing #2: Electronic Computing
- Crash Course Computing #3: Boolean Logic and Gates
- Crash Course Computing #4: Representing Numbers and Letters in Binary
- Crash Course Computing #21: Compression This makes some references to things you won't have heard about yet because they are in videos you will watch later in our course. However, you should be able to follow the main ideas of the video.
- Extra 1.1 https://www.youtube.com/watch?v=Xpk67YzOn5w (How does binary work, how can numbers represent ASCII. Very similar to a previous video but may still be worth watching.)
- Extra 1.2 https://www.youtube.com/watch?v=PZRI1IfStY0 (Why rounding errors occur in binary.)
- Extra 1.3 https://www.youtube.com/watch?v=15aqFQQVBWU (Code.org video on picture encodings)
The following were UNI produced supplemental videos.
- Understanding Logic Gates (1a)
- From binary to integers (1b)
- From integers to binary (1b)
- From binary to hex (1b)
- Explanation - binary strings to fractions (1c)
- Explanation - fractions to binary strings (1c)
- Floating Point Representations (1c)
- Storage Errors (1c)
- Encoding text in binary (1d)
- Compression of text (1e)
- Compression of pictures (1e)
Study Guide
The competency demo for this chapter will consist of several questions from the following study guide. As you study this chapter we suggest you work through the materials in this study guide and ask questions if you need clarifications.