Virtual memory

Process (computing)

Thread (computing)

Pointer (computer programming)

MapReduce

Array (data structure)

Memory allocation

Buffer overflow

Synchronization (computer science)

Digital Logic

Transistors to Gates

Data as Bits

Software Tools

Integer Representation

Combinational Logic

Arithmetic Logic

Sequential logic

Processor Datapath

Floating Point Number Representation

Programming with Memory

C Pointers

C Arrays

Call stack

Representing Data Structures

Memory hierarchy

Exceptional Control Flow (ECF)

Process modeling

Shell (computing)

CS 240 Foundations of Computer Systems Wellesley College Spring 2023 This course explores the inner workings of computers, focusing on how they execute programs. Students gain an in-depth understanding of software and hardware abstractions, ranging from programming languages to transistors. Key areas covered include computational building blocks, hardware-software interfaces, data representation, and practical system abstractions. The course also emphasizes structured reasoning about program execution and promotes skills for independent learning, critical thinking, and problem-solving in computer science. CS 240 examines how computers run programs, introducing key abstractions and implementations in software and hardware between programming languages and transistors. ## Goals

Course goals include:

- To understand how computers execute programs.
- To understand the roles of key software and hardware abstractions, their implementations, and their relation through translation and representation, including: digital logic, microarchitecture, instruction set architecture, the memory hierarchy, basics of programming language implementations, and operating system abstractions.
- To understand when and how computer system implementation impacts correctness or performance of arbitrary high-level programs.
- To become proficient in structured reasoning about the execution of programs on well-defined models, including the use of assertions and debugging tools to inspect program invariants and execution state.
- To develop foundations for further study of programming language implementation, security, computer architecture, operating systems, networks, concurrent and distributed systems, or other systems/implementation topics in computer science.
- [**To develop skills for independent learning, critical thinking, and problem-solving as a self-reliant computer scientist.**](#compact)

## Topics

The [course home page](https://cs.wellesley.edu/~cs240/s23/) hosts the working schedule. +Optional extensions are prefixed in the schedule with a plus sign. We may visit these if there is time. They are always available for your own exploration in further depth.

**Computational Building Blocks:**

- Hardware computation building blocks: 
    - Transistors, digital logic gates
    - Combinational and arithmetic logic
    - Sequential (stateful) logic
    - Overview of computer processor architecture
- Data representation fundamentals: 
    - Data representation with bits, bit-level computation
    - Number representation, arithmetic
    - The memory model, pointers, and arrays in the C language
    - Assertions, debugging

**Hardware-Software Interface:**

- The instruction set architecture model, machine code, assembly language, x86
- Basic program translation
- Control flow
- Procedures, call stack
- Data layout, security implications

**Abstractions for Practical Systems:**

- The memory hierarchy, caches
- Memory allocation
- Operating system basics: 
    - Exception control flow
    - The process model
    - Virtual memory
- Compilers, run-time systems, programming tools
- Beyond 240 ### When Should You Take CS 240?

**Prerequisite:** CS 230 or permission of the instructor is **required** to enroll in CS 240.

**Recommendations:**

- Consider your courseload carefully. CS 240 is a 1.25-credit lab course that requires a larger time commitment and workload than most 1-credit courses.
- Take CS 240 early after finishing the CS 111 / CS 230 introductory sequence. CS 240 should boost your independence, give valuable context for *how things work* as you approach further computing studies, and open doors to a wide range of courses and areas in CS.

Please talk to the [instructors](#staff) if you have any questions or concerns. We are happy to work with you to make your time in CS 240 most effective and rewarding for you. ### Texts

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*](https://drive.google.com/drive/folders/1eFNJ7GqAHH8_W4dNv0UC4qkZX-kEMQH_?usp=sharing)):   
    [*Computer Systems: A Programmer’s Perspective, 3/E*](http://csapp.cs.cmu.edu). (**3rd edition**, significant changes since 2nd)   
    Bryant and O’Hallaron, Pearson, 2016. ISBN-13: 9780134092669. 
    - We **need the 3rd edition**. See [the errata](http://csapp.cs.cmu.edu/3e/errata.html).
    - 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.](https://www.vitalsource.com/products/computer-systems-a-programmer-39-s-perspective-randal-e-bryant-david-r-v9780134092997)
        - During difficult pandemic circumstances, [we have scans of the relevant excerpts available for CS 240 students (Wellesley ONLY)](https://drive.google.com/drive/folders/1eFNJ7GqAHH8_W4dNv0UC4qkZX-kEMQH_?usp=sharing). 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*](https://ebookcentral.proquest.com/lib/well/detail.action?docID=404196)):   
    [*Digital Design and Computer Architecture*](https://ebookcentral.proquest.com/lib/well/detail.action?docID=404196).   
    Harris and Harris, Morgan Kaufmann, 2007. 
    - [The library has an electronic version of this text](https://ebookcentral.proquest.com/lib/well/detail.action?docID=404196)

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

- **[Essential C](http://cslibrary.stanford.edu/101/)** (PDF)  
    Nick Parlante, 2003. Stanford University.
- **K&amp;R:**  
    [*The C Programming Language, 2nd edition*](http://luna.wellesley.edu/record=b1630956~s1).   
    Kernighan and Ritchie, Prentice Hall, 1988. ISBN-13: 978-0131103627, ISBN-10: 0131103628.

**Additional materials** will be posted directly on the [course website](/~cs240/s23/).

CS 240 Foundations of Computer Systems

Machine organization

String (computer science)

Vector (C++)

System Programming

struct (C programming language)

Data structure alignment

Collection Summary

Signed number representations

Assembly language

Calling Conventions

Stack (abstract data type)

Caching

Operating system

Privilege separation

Memory protection

Page table

Process Control

Inter-Process Communication (IPC)

Race condition

Synchronization Patterns

Deadlock

Networking

Scalability

Distributed Scalability

Failures

Consistency (database systems)

Real-world Distributed Systems

CS 131: Fundamentals of Computer Systems Brown University Spring 2020 This course delves deep into the foundational principles behind computer systems, ranging from hardware intricacies to the vast global internet. Students gain insights into systems programming, the architecture of computer systems, concurrency, and the dynamics of distributed systems. Notably, the curriculum includes projects that offer hands-on experience, like building library functions, creating a toy OS, and designing a scalable key-value storage service. It's a stepping stone to advanced courses like Distributed Systems, Databases, and Computer Systems Security. The goal of **CS 131/CSCI 1310** is to teach the fundamentals behind the "magic" of computer systems from the hardware level to the global internet. We'll cover the ideas, principles and abstractions that unify computer systems design – from how your laptop runs multiple programs at the same time, to how companies like Instagram, AirBnB, and Google operate large websites, to how easy it is to exploit security vulnerabilities on badly designed systems. This is a great class for students who are interested in learning **what** systems programming is, **how** systems work, and **why** these systems are so critical to modern technology. We will look at topics arranged in four main blocks during the course, building up your understanding across the whole systems stack:

1. **Computer Systems Basics**: programming in systems programming languages (C and C++); memory; how code executes; and why machine and memory organization mean that some code runs much faster than other code that implements the same algorithm.
    *Project*: you will build your own versions of standard library functions and a vector data structure (strvec), and you will develop your own debugging memory allocator, helping you understand common memory bugs in systems programming languages (DMalloc).
1. **Fundamentals of Operating Systems**: how your computer runs even buggy or incorrect programs without crashing; how it keeps your secrets in one program safe from others; and how an operating system like Windows, Mac OS X, or Linux works.
    *Project*: you will implement memory isolation via virtual memory in your own toy operating system (WeensyOS)!
1. **Concurrency and Parallel Programming**: how your computer can run multiple programs at the same time; how you can share memory even if running programs on multiple processors; why programming with concurrency is very difficult; and how concurrency is behind almost all major web services today.
    *Project*: you will implement the server-side component of a peer payment application called "Vunmo", and make it handle requests from many users.
1. **Distributed Systems**: what happens when you use more than one computer and have computers communicate over networks like the Internet; how hundreds of computer can work together to solve problems far too big for one computer; and how programs running distributedly can survive the failure of participating computers.
    *Project*: you will implement a sharded key-value storage service that can (in principle) scale over hundreds or thousands of machines.

The first block, Computer Systems Basics, begins today. It's about how we represent data and code in terms the computer can understand. But today's lecture is also a teaser lecture, so we'll see the material raise questions that you cannot yet answer (but you will, hopefully, at the end of the course!). CS 131/CSCI 1310 is open to anyone who has completed the introductory sequence (i.e., CS 16, 18, or 19). For students who don't satisfy the registration restrictions on CAB, please request an override code on CAB and include an explanation of your course experience, and we'll review your request. **What does CS 131 count for?** CS 131/CSCI 1310 is a 1000-level course that can count as a related course in the systems pathway of the CS concentration and masters. In addition, CS 131 will satisfy the prerequisites for CSCI 1380 (Distributed Systems), CSCI 1270 (Databases), CSCI 1650 (Software Security and Exploitation), CSCI 1660 (Computer Systems Security), CSCI 1730 (Programming Languages), CSCI 1951-A (Data Science), CSCI 1680 (Computer Networks), and CSCI 2390 (Privacy-Conscious Computer Systems).

CS 131: Fundamentals of Computer Systems

C Programming

Memory representation

Control flow

Address translation

Inter-process communication

Pipeline (Unix)

Multiprocessing

Atomic instructions

Mutexes (Mutual exclusion)

Bounded-buffer problem

Condition variables

CSCI 0300: Fundamentals of Computer Systems Brown University Spring 2023 Introductory course covering computer system fundamentals including machine organization, systems programming in C/C++, operating systems concepts, isolation, security, virtualization, concurrency, and distributed systems. Projects involve implementing core OS functionality. CSCI 0300 covers fundamental concepts, principles, and abstractions that underlie the design and engineering of computer systems. You will learn how a computer works, how to write safe and performant systems software, and what systems abstractions support today's complex, high-performance systems developed in industry. Specific topics include machine organization, systems programming and performance, key concepts of operating systems, isolation, security, virtualization, concurrent programming, and the basics of distributed systems.

The course format is a combination of lectures, labs, and several hands-on projects involving programming exercises in C/C++. The goal of CSCI 0300/CS 300 is to teach the fundamentals behind the "magic" of computer systems from the hardware level to the global internet. We'll cover the ideas, principles and abstractions that unify computer systems design – from how your laptop runs multiple programs at the same time, to how companies like Instagram, Airbnb, and Google operate large websites, to how easy it is to exploit security vulnerabilities on badly designed systems. This is a great class for students who are interested in learning what systems programming is, how systems work, and why these systems are so critical to modern technology. This is an introductory computer systems course, designed to expose students to a broad set of fundamental concepts in computer systems and their practical applications. It is best suited for students who have completed the intro sequence, and to those who may want to deepen their understanding of systems concepts. Programming languages used in assignments include C and C++. ## CSCI 0300 highlights

- *Learn how a computer really works:* we'll look into what happens when a program runs, from the basics to high-level concepts!
- *Use industry-strength tools:* CSCI 0300 teaches you modern C/C++ programming with the tools that professional software engineers use!
- *Two programming languages for the price of one:* learn C and C++, two widely-used systems programming languages for high-performance software!
- *Real-world inspired projects:* in CSCI 0300's projects, you'll implement the core of your own operating system, and learn to build scalable infrastructure such as a distributed data store and a multi-threaded server similar to those companies use to run web services you use every day!

CSCI 0300: Fundamentals of Computer Systems

Set Architectures

Microcode

Verilog

Pipelining

Cache (computing)

Superscalar

Exception handling

Very long instruction word (VLIW)

Superpipelining

Branch Prediction

Vector Processors

Graphics Processor (GPU)

Multithreading

Parallel Programming

Small Multiprocessors

Multiprocessor Interconnect

Large Multiprocessors

Directory Protocols

ELE/COS 475 Computer Architecture Princeton University Fall 2019 This course offers an in-depth understanding of modern computer processor and system architecture. It covers topics like instruction-set architecture, processor organization, cache, memory, multiprocessors, and more. Designed for senior-level undergraduates and first-year graduate students. An in-depth study of the fundamentals of modern computer processor and system architecture. Students will develop a strong theoretical and practical understanding of modern, cutting-edge computer architectures and implementations. Studied topics include: Instruction-set architecture and high-performance processor organization including pipelining, out-of-order execution, as well as data and instruction parallelism. Cache, memory, and storage architectures. Multiprocessors and multicore processors. Coherent caches. Interconnection and network infrastructures. If the course indicates that enrollment capacity has been reached, students are encouraged to come to the class and speak with the professor about enrollment. Approximately 20 pages of reading per week. Homework - 5 problem sets during the semester.  This course is targeted at senior-level undergraduates and first-year graduate students. Students should have a good working understanding of digital logic, basic processor design and organization, pipelining, and simple cache design. ELE 375/COS 375 and ELE 206/COS 306 or equivalent knowledge are necessary to succeed in ELE 475. Use of the Verilog hardware description language will be used in this course and prior knowledge of Verilog will be very helpful, but not required. **Required text:**

1.  Computer Architecture: A Quantitative Approach 5th or 6th edition
    -  John L. Hennessy and David A. Patterson
    -  Princeton University Library Owns

**Recommended Text:**

-  Modern Processor Design: Fundamentals of Superscalar Processors (1st Edition), 2004. First and second printing are the same.
    -  John P. Shen and Mikko H. Lipasti
    -  Approximately $68 on [Amazon](http://www.amazon.com/Modern-Processor-Design-Fundamentals-Superscalar/dp/1478607831/ "http://www.amazon.com/Modern-Processor-Design-Fundamentals-Superscalar/dp/1478607831/")
    -  ISBN: 978-1478607830
    -  Princeton University Library Owns

**Other Text:**

-  Verilog HDL: A Guide to Digital Design and Synthesis, (2nd Edition), 2003.
    -  Samir Palnitkar
    -  ISBN: 0-13-044911-3
    -  This book is a good Verilog reference as we will be using Verilog in the labs for this course. If you already know Verilog for synthesis than this may not be needed. The 1st and 2nd editions of this book work. Likewise there are many other Verilog references on the web and other books are available.
    -  The 1st edition can be purchased used from Amazon for less than $10, the 2nd edition is more expensive.
    -  Princeton University Library has free online access to this book: [Online Safari Version On Princeton Network](http://proquest.safaribooksonline.com/?uiCode=princeun&xmlId=0130449113 "http://proquest.safaribooksonline.com/?uiCode=princeun&xmlId=0130449113")

ELE/COS 475 Computer Architecture

Filesystems

System Calls

File Descriptors

waitpid

execvp

Interprocess Communication

Signals

Semaphores

Multithreading Patterns

Thread Pools

Read-Write Locks

Parallel Compilation

Networks

Clients

Servers

HTTP

API (Application Programming Interface)

Networking Functions

CS 110: Principles of Computer Systems Stanford University Winter 2022 CS 110 delves into advanced computer systems and program construction, focusing on designing large systems, software that spans multiple machines, and parallel computing. This course builds upon CS107 and requires good knowledge of C, C++, Unix, GDB, Valgrind, and Make. It covers Linux filesystems, multiprocessing, threading, networking, and more. CS107 took you behind the scenes:

- how things work inside C++/Python/Java, and how your programs map onto the components of computer systems
- understanding of program behavior and execution
 
CS110 uses this as a foundation to build complex programs that maximally take advantage of the hardware and operating system software available to us:

- How can we understand the designs and tradeoffs of large systems?
- How can we write software that spans multiple machines?
- How can we write software that runs tasks in parallel on a single machine? ### Course Topics Overview

1. **Overview of Linux Filesystems** - How can we design filesystems to store and manipulate files on disk?
1. **Multiprocessing and Exceptional Control Flow** - How can our program create and interact with other programs?
1. **Threading and Concurrency** - How can a single instance of our program perform multiple coordinated tasks at the same time?
1. **Networking and Distributed Computing** - How can we write programs that communicate over a network with other programs, and tackle large tasks using many machines?
1. **Additional Topics**: MapReduce, Caching, and Non-Blocking I/O **CS107 or equivalent -**

- Each of you should know C and C++ reasonably well so that you can...
    - write moderately complex programs (e.g. pointers, **malloc/realloc/free**, C strings, C++ classes, methods, references, templates, **new/delete**)
    - read and understand portions of large code bases
    - trace memory diagrams and always win!
- Each of you should be ﬂuent with **Unix, GDB, Valgrind**, and **Make** to the extent they're covered in CS107 or its equivalent.

The first assignment is meant to give you a sense of the scope of CS110 programs and refresh your memory on relevant prerequisites.  If you feel ok about it, you're all set! Second half of CS107 Textbook: *Computer Systems: A Programmer's Perspective by Bryant & O'Hallaron, 3rd Edition*

- Can purchase full copy, or Stanford Bookstore custom edition with just CS110 chapters
 
*Principles of Computer System Design: An Introduction* by Jerome H. Saltzer and M. Frans Kaashoek

- Free Stanford online access [here](https://www.sciencedirect.com/book/9780123749574/principles-of-computer-system-design)​ (also linked on course homepage)
- Fewer readings from this book vs. first one
- You're welcome to buy a physical copy if you'd like

CS 110: Principles of Computer Systems

Computer Systems, a.k.a. Computer Architecture, is about the design and organization of computer systems, and how the hardware and software components interact with each other. Its applications includes software development, computer hardware design, computer systems engineering etc.

Computer Systems

Computer Science

Computer Systems

Prerequisites

Common concepts