📚 Topics

Contents

• Textbooks
• Preparing for Class Meetings
  • How to watch videos for CS 240
  • How to read for CS 240
• Material by Topic
  • The Plan
• Computational Building Blocks
  • Digital Logic
  • Data as Bits
  • Integer Representation
  • Combinational Logic
  • Arithmetic Logic
  • Sequential Logic
  • A Simple Processor
• Hardware-Software Interface
  • Programming with Memory
  • x86 Basics
  • x86 Control Flow
  • x86 Procedures, Call Stack
  • Representing Data Structures
  • Buffer Overflows
• Abstractions for Practical Systems
  • Memory Hierarchy, Cache
  • Memory Allocation
  • Exceptional Control Flow
  • Process Model
  • ⁺Shells, Signals (optional)
  • Virtual Memory
  • Compilers, Runtime Systems
  • Beyond 240

Textbooks

Electronic options are available for all required sources. At least one physical copy of each text is also available in the physical SCI L037 CS Systems Lab for use within the CS department area. Please use them in the data lab area and return them to the shelf when you are done.

We use one primary textbook extensively:

• CSAPP 3e (Wellesley online access):
  Computer Systems: A Programmer’s Perspective, 3/E. (3rd edition, significant changes since 2nd)
  Bryant and O’Hallaron, Pearson, 2016. ISBN-13: 9780134092669.
  • We need the 3rd edition. See the errata.
  • Unfortunately, the library is not able to acquire an electronic version, but there are several options to access the book, including, but not limited to:
    • If you prefer physical books, paperback copies are available for much less than the hardcover version. “Global” 3rd editions mostly work, but have some additional errors (not listed on the errata page).
    • 6 months of access to an electronic version is available for $35.
    • During difficult pandemic circumstances, we have scans of the relevant excerpts available for CS 240 students (Wellesley ONLY). Being scans, these excerpts are not quite as good quality as some other electronic or paper options.
  • Please contact the instructors if none of the available options work for you.

Other textbooks are used during the first part of the course:

• DDCA (Wellesley online access):
  Digital Design and Computer Architecture.
  Harris and Harris, Morgan Kaufmann, 2007.
  • The library has an electronic version of this text

We recommend a good reference on the C programming language. Here are a couple solid options:

• Essential C (PDF)
  Nick Parlante, 2003. Stanford University.
• K&R:
  The C Programming Language, 2nd edition.
  Kernighan and Ritchie, Prentice Hall, 1988. ISBN-13: 978-0131103627, ISBN-10: 0131103628.

Additional materials will be posted directly on the course website.

Preparing for Class Meetings

Before each class meeting, complete the required preparation steps listed in the topics for the day. Preparation varies from day to day, but usually consists of some combination of watching videos, reading, or trying small exercises, and asking or answering questions on Zulip. Expect the preparation to take more than a few minutes. Synchronous class activities will build on ideas in preparation material.

How to watch videos for CS 240

Many topics will have videos attached. When asked to watch these videos for preparation, or if you use them for reference at any time:

• You can view them on YouTube (nocookie version without tracking) or download/watch the MP4 files directly.
• Take notes like you would in class.
• You might find it helpful to download a copy of the slides to follow along or take notes.
• It’s fine to pause and take breaks whenever you want!
• You do not need to watch all the videos from one topic or even all the videos assigned for one day of preparation in one sitting. The videos are usually broken up into chunks usually between 5 and 15 minutes length, occasionally a little shorter or longer.
• When the talking head says to “try this,” pause the video to freeze the talking head in a bizarre pose, then actually try the example, just like you would in class when we do an exercise together.

How to read for CS 240

Effective reading for computer science courses demands a staged approach. Aim for two types of reading:

• Do an initial reading in preparation for the class when the topic is scheduled.
• Revisit the reading later for deeper details or reference.

Before class, do an initial reading of the any reading material assigned as preparation for class.

Do not worry about understanding every last detail.

Do aim to acquire:

• A big-picture view of the pieces we will consider about this topic.
• Some familiarity with basic mechanics of the ideas introduced.

To help distinguish core points from secondary concerns during initial reading, each reading is listed with one of two style directives:

• Read means read for enough detail to do indicated reading exercises. If you do get stuck or confused by some details, do not worry. Make a note and move on. If we do not clear up your confusion in class, ask a question or come to office hours.
• Skim means read for high-level ideas. Perhaps pick out a couple details that look interesting and accessible. Do not spend much time trying to understand all the details before moving on.

Learning how to identify essential vs. inessential details during a first reading is an important skill that takes time to develop. As the semester progresses, we will leave more of this to you.

Readings assignments may indicate specific exercises to try as you read before class. These are typically practice problems from the reading.

• Try means work through enough of the exercise to see how the basics work. Do not feel obligated to finish every example. Do what is useful to you. (Do not submit anything.)

We typically highlight exercises that practice mechanics. Feel free to try other practice problems as well. They may require more time and critical thinking. We will explore such interesting examples in class.

After class, revisit readings in more depth and try more practice problems to work out details as needed.

More advice for reading

Our main text (CSAPP) sometimes goes into more detail than we will cover, so learning to “read around” extra detail is a useful skill, especially in your pre-class reading.

When reading from CSAPP:

• “Asides” are optional. If you read them, skim them.
• “New to C?” blocks can be useful, but usually only if they are short.
• Some sections (e.g., 2.2 - 2.4 on integer and floating point representations) can be too dense for our purposes. We try steer you around them, but if you find other things getting dense, flip to another reading or just make a note and jump ahead.
• This book really shines with later material about machine/assembly language, caching, memory management, and other topics. We use it intermittently in the first section of the course, then extensively for the latter two.

Tia Newhall (Swarthmore College) has more good advice on reading computer science textbooks.

Material by Topic

This list of topics includes:

• Topics covered in class meetings, with preparation directions and listings of all lecture materials, associated readings, and activities.
• ⁺Optional items that offer opportunities to explore further, but are not required.

Computational Building Blocks

Hardware-Software Interface

Abstractions for Practical Systems