General Information and Syllabus

Based on a document by Julie Zelenski, Cynthia Lee, Jerry Cain, John Ousterhout, and others
Last updated September 25, 2022

Instructor: Nick Troccoli (troccoli @ stanford.edu).
Helper Hours on helper hours calendar
All course staff: See front page

Course Essentials

  • The class website for CS111 is located at https://cs111.stanford.edu. Please regularly check the course website as we will post important announcements there, as well as the course schedule, lecture materials, handouts, assignments, and more.

  • We will have lecture on Mondays, Wednesdays and Fridays, 11:30AM - 12:20PM in STLC 111.

  • We will be using Canvas to store lecture recordings and access Zoom links for remote helper hours. Access our Canvas course.

  • We will be using Poll Everywhere to record lecture participation and do in-class polls. Access Poll Everywhere with your Stanford email here.

  • The discussion forum on Ed is the place for students to ask questions and discuss course topics with peers and staff. Visit helper hours if you have more specific debugging or conceptual questions.

  • The myth servers (accessible via ssh) are our remote workspaces for completing programming assignments. Read more in our getting started guide

Course Overview

CS111 is Stanford's introductory operating systems course. The CS106 courses provide you with a solid foundation in programming methodology and abstractions, and CS107 builds up and expands your breadth and depth of programming experience and techniques, working from the C programming language down to the microprocessor to de-mystify the machine. CS111 leverages this programming experience to introduce operating systems and how they work. With an understanding of both how to leverage operating system functionality in your own programs as well as how operating systems manage tasks behind the scenes, you will have a better understanding of how operating systems work, the kinds of design challenges present in operating systems and other large systems, and key computing ideas such as virtualization that are applicable in many different areas. Topics covered include: filesystems, system calls, concurrency, multiprocessing, multithreading, race conditions, synchronization primitives, virtual memory, demand paging and operating system design challenges.

CS111A

CS111A, also called Pathfinders (or ACE), is a supplementary instruction program that meets for a weekly section and holds Pathfinders-specific review sessions. CS111A is application-only; CS111A is done in addition to all the normal requirements for CS111. You will receive an extra unit of course credit for the work you do in this program. Enrollment in CS111A is by application, and you can find more information at this link: click here. Once enrollment decisions are made, students who are accepted will then be given a permission number to enroll in CS111A on Axess. If you have questions about CS111A, please email the ACE CA (contact information listed on the course homepage).

Prerequisites

The prerequisite for CS111 is CS107 (or equivalent). You should have practical C/C++ skills and be able to write programs with complex use of memory and pointers and dynamic memory allocation (malloc/realloc/free/new/delete). You should understand C++ classes, methods, and be able to work with appropriate data structures (arrays, maps, etc.) and standard algorithms (searching, sorting, hashing). (There are C++ features you're not expected to know, but you should be comfortable picking those features up and consulting references as needed). You should be familiar with programming in a Unix/Linux environment using tools such as make, gcc/g++, valgrind, gdb, etc. and have a working understanding of the basics of computer architecture (x86-64 as it’s taught in CS107, or exposure to some other architecture and the ability to pick up x86-64 as we reference it). Come talk with us if you need help determining the right placement for you.

Units

If you are a matriculated Stanford graduate student, you may enroll in CS111 for 3-5 units based on your schedule. Otherwise, you are required to enroll in CS111 for 5 units. In particular, anyone enrolled as a Stanford undergraduate must register for the full 5 units, or you will not be assigned a grade in the course. Taking the course for reduced units does not alter the course requirements.

Guiding Principles

We have designed the course to the best of our ability to provide flexibility. There are campus resources, such as accommodations, undergraduate advising directors, well-being coaches, counselors, academic coaches, Hume Center writing tutors, and the FLI opportunity fund for broader needs you might have. For information about specific policies and procedures for the quarter, Student Affairs has the most up-to-date information for students. If there are additional ways we can support you in the course, please feel encouraged to reach out to us. Without requesting or expecting details of your situation, we will do everything we can to ensure your course learning is productive and enjoyable.

Course Accommodations

If you are ever sick, in COVID-19 isolation, encounter an emergency, or other exceptional circumstance, we have a variety of accommodation mechanisms for each course component, and we encourage you to reach out to the instructor or course staff to let us know how we can help! The accommodation mechanisms include:

  • late days on assignments (see assignment late policy)
  • attending a makeup section or getting an excused section absence (see sections)
  • lecture excused absences (see lectures)
  • accommodations for exams due to illness, COVID-19 isolation, or other emergency (see exams)
  • students who are ill, in COVID-19 isolation, have an emergency, or other exceptional circumstances may temporarily attend all helper hours remotely with instructor permission (see Getting Help)

If you feel ill or are sick, for the wellbeing of yourself and others please stay home, take care of yourself, take advantage of these accommodations, and reach out to us - we never want you to feel that you must attend class if you are not feeling well! Similarly, if you have an emergency or exceptional circumstance, please take advantage of these accommodations and reach out to us so that we can help.

Course Environment

In CS111, there will be significant programming assignments and you can expect to work hard and be challenged by this course. Your effort can really pay off - once you understand operating systems and how to maximally take advantage of the hardware and operating system software available to you, you will have powerful skills to bring to any future project! To make that happen for everyone, we strive to create an inclusive and equitable class. We further depend on you to help each other obtain excellence rather than mistaking Stanford or this class as zero-sum. We ask that you do your part by seeking to promote the success of others, and by treating each other in ways that respect and celebrate the diversity of talent that is drawn to our exciting field of Computer Science. Here are several aspects of our policy for creating an inclusive and equitable class:

  • Preparation: Perhaps more than many other subjects, students come to computer science with greatly varying previous exposure to the subject. Regardless of your background, as long as you meet the course prerequisites, you are well-prepared to succeed in CS111. Just ask the students who are now your TAs!

  • Classroom Environment: We are happy to answer questions you have through various course support channels (helper hours, discussion forum, etc.). However, during lectures, we request that any questions you ask be clarifications for yourself or others of the course material being discussed, rather than a question or comment intended to demonstrate additional knowledge beyond the scope of the current topic or the course, which may intimidate or discourage other students. If you do have such questions or comments, we are more than happy to discuss them during helper hours, or before/after any lecture!

  • Access and Accommodations: Stanford is committed to providing equal educational opportunities for disabled students. Disabled students are a valued and essential part of the Stanford community. We welcome you to our class. If you experience disability, please register with the Office of Accessible Education (OAE). Professional staff will evaluate your needs, support appropriate and reasonable accommodations, and prepare an Academic Accommodation Letter for faculty. To get started, or to re-initiate services, please visit oae.stanford.edu. If you already have an Academic Accommodation Letter, we invite you to share your letter with us. Academic Accommodation Letters should be shared at the earliest possible opportunity so we may partner with you and OAE to identify any barriers to access and inclusion that might be encountered in your experience of this course.

  • Name and Pronouns: We want you to be you in our class. You are always welcome to put your preferred name on all classwork and exams. If you have a name and/or pronoun that doesn’t match our registrar-provided class roster, please let us know and we will ensure that we use it in our class.

  • Course Expenses: If obtaining any material or resource for use in our class presents a financial hardship for you, please let us know and we will work with you to accommodate.

  • Feedback: Please do not hesitate to reach out to the course staff or the instructor, anonymously if you prefer (there is an anonymous feedback link on the main page of the course website), if any aspect of our course or community can be improved.

Course Structure

Course Grades

Final grades for the course will be determined using the following weights:

  • 55% Assignments
  • 5% Section Participation
  • 5% Lecture Participation
  • 15% Midterm Exam
  • 20% Final Exam

Final course grades will be calculated by determining the raw overall score, and then breaking the score distribution into different letter grades. We do not decide these letter grade cutoff points until the end of the quarter, based on the course distribution - for that reason, we cannot guarantee in advance that a particular raw overall score will translate to a particular letter grade.

If you choose to take the course CR/NC, your final grade must be satisfactory or better--in other words, you need a C- or better to get a CR.

Lecture

Lectures are held in person on Mondays, Wednesdays and Fridays. Because CS111 is not on SCPD (for professional development students) this quarter, the course is not officially recorded. (You can find a full list of when courses are offered on SCPD here). However, we have recording equipment provided in the lecture hall and will do our best to record each lecture ourselves and upload them to Canvas within a few hours of lecture. Please note that because recordings are done manually, there may be quality issues and some content may be lost; we will do our best to minimize any issues, but can't make any guarantees.

Lecture attendance/participation is recorded via Poll Everywhere. Students who submit answers to all questions during a lecture (regardless of response correctness) will receive credit for attending that lecture. If you are ill, in COVID-19 isolation or have other extenuating circumstances and cannot attend lecture on a given day, we will permit 5 excused absences across the quarter - you do not need approval from the course staff for these 5 absences. Beyond these 5 absences, we will grant additional excused absences only in cases where you have already used your 5 excused absences for extenuating circumstances and further extenuating circumstances necessitate additional accommodations. You shouldn't use your excused absences except in extenuating circumstances (illness, COVID-19 isolation, emergency, etc.) - doing so risks situations later in the quarter where an unexpected situation arises and you have no remaining absences left! Only the instructor will be able to approve additional excused absences. Please do not hesitate to reach out to the course staff or the instructor if any personal circumstances or issues arise!

Additionally, a small portion of this lecture attendance/participation grade will also come from a very short course feedback survey that we ask you to fill out twice over the course of the quarter. The feedback should only take a few minutes, and will be used to understand how the course is going, and to help make it better. An automated system will email you at the start of two different weeks during the quarter asking for this short feedback to be submitted sometime by Friday of that week. Each student will only receive 2 requests during the quarter. Of course, you are welcome to provide feedback during other weeks in addition to the ones to which you are assigned through the anonymous course feedback form at the bottom of the course homepage (or click here.) We greatly appreciate any feedback you have to improve the course!

Sections

In addition to lecture, you must also sign up for a weekly 50-minute in-person section led by one of our CAs. Each section will have about 10-14 students, and in section, students work together and in small groups on guided exercises. Sections encourage participatory collaborative learning - the goal is for everyone to come away with a clear understanding of the section concepts and be prepared to go on to individually complete the assignments.

Part of your course grade comes from arriving on time, attending, participating in and completing the work in your section each week. At the end of the section, you will submit a checkoff sheet to record your section participation / attendance grade. Arriving late or leaving early will result in not receiving section credit.

You must submit your section time preferences using a link posted on the main course webpage starting on Tue Sep 27 5:00 pm PDT. Note that signups are not first-come, first-serve; you may submit your preferences any time up to Sat Oct 1 9:00 pm PDT. You may also come back and update your preferences until this time as well. Our typical weekly schedule offers sections Wed, Thurs and Friday at various times throughout the day. Sections begin the second week of classes. Note that you must sign up for sections via the course website (you do not sign up for sections on Axess).

If you cannot make your section during a given week, you may attend a section other than your assigned one as a "visitor". Visitors are accommodated when space is available, but priority is given to the assigned students. Please tell the section TA at the beginning of your visiting section that you are visiting so that they are aware. We ask that you please attend your assigned section unless extenuating circumstances (illness, COVID-19 isolation, emergency, etc.) prevent you from attending. Students find that they learn best with a regular timeslot, the same section TA, and a recurring section group, and too many visitors to a single section may mean we will be unable to accommodate all visitors.

If you have an extenuating circumstance (illness, COVID-19 isolation, emergency, etc.) and cannot make any sections during a given week, please email the instructor for accommodations. Otherwise, if you do have to miss attending the section entirely, we strongly encourage you to work through the exercises for your own benefit, but there is no makeup credit for missed participation.

Assignments

There will be six assignments throughout the quarter, all of which are to be done individually. Assignments are due at 11:59pm PT sharp on the dates specified and are written and submitted electronically using the myth cluster of Unix workstations in the Gates Computer Science Building. These machines are accessible remotely from other machines such as your personal computer, and they are pre-installed with all software used for sections and assignments. Students edit, compile, and debug on the myth systems using a suite of open source development tools including gcc/g++, make, gdb, and valgrind.

Assignments may consist of written portions and coding portions, and are graded and returned to you electronically via the course website. The course staff grades each programming portion on functionality (is the program’s behavior correct from an external perspective?). We do not review/grade assignments on coding style - but good coding style will be essential for writing code that is easier to reason about, maintain, debug, and develop. For some assignments, TAs may do limited code review for certain functionality issues.

Functionality is measured by how successfully the program executes on a comprehensive set of test cases. We create our test suite by working from the original program specification to identify a list of expected behaviors and write a test case for each. We use the autotester to run a submission on each test and award points for each successful result. Thus, the resulting functionality score is a direct reflection of how much observably correct behavior your program exhibited. This process is completely automated; the grader does not search your code to find bugs and deduct for them, nor do they appraise the code and award points for tasks that are attempted or close to correct.

All assignments are weighted equally.

Disputes about homework grading must be submitted to the course staff within 1 week of receiving your grade. For more information about the assignment grading process, please see our page on how assignments are graded.

Assignment Late Policy

Every student begins the quarter with five free "late days," to be used only for assignments. Each late day allows you to submit an assignment up to one calendar day late without penalty. For example, if a due date is Wednesday at 11:59PM PT, using 1 late day allows you to submit until that Thursday at 11:59PM PT without penalty, and 2 late days allows you to submit until that Friday at 11:59PM PT without penalty. Late days may only be used in 24-hour increments. We will not accept assignments more than 2 days late and no late days may be used for the final assignment.

After the late days are exhausted, submissions that come in late will be assessed a late penalty per day late. Specifically, if you submit up to 1 day late, your score will be capped at 80% of possible points. This means that if you have a score above 80%, then your score will be lowered to 80%. If you have a score at or below 80%, your score will remain the same. Similarly, if you submit between 1 and 2 days late, your score will be capped at 60% of possible points.

You should think of free late days as extensions you have been granted ahead of time and use them when you might have otherwise tried to ask for an extension. Beyond these 5 late days, we will grant additional extensions only in cases where exceptional circumstances necessitate more than a 2-day extension, or when you have used your 5 late days and further extenuating circumstances necessitate additional accommodations. As a result, getting an extension for exceptional circumstances beyond the provided free late days must be approved by the instructor. Only the instructor will be able to approve extensions. In particular, do not ask the CAs. All extension requests must be received in advance of the assignment deadline. Please do not hesitate to reach out to the course staff or the instructor if any personal circumstances or issues arise!

Examinations

The midterm examination is in-person and will be administered outside of class from 7-9PM PDT on Tuesday, November 1. If you have an academic or University conflict with this time, and absolutely cannot make the regularly scheduled midterm, you must send a request by email to the course staff by 11:59PM on Wednesday, October 26 to arrange an alternate exam time. Please include in your email all the possible times you are able to take the exam from Monday, October 31 to Wednesday, November 2. Any alternate midterm exam must be within this window.

The final examination is in-person and scheduled for Friday, December 16 from 8:30-11:30AM PDT. There will be no alternate time for the final exam, except for those with relevant official university athletics or Office of Accessible Education accommodations. Please make sure that you can attend the final exam at the specified time before enrolling in the class.

All examinations are administered electronically and are closed-book; however, you will be allowed to bring in one double-sided 8.5x11" page of notes. A reference sheet will be provided to you during each exam, as well as beforehand for studying, containing commonly-needed information. No other materials may be used.

If you become ill, must enter COVID-19 isolation, or have another emergency around the time of or during an exam, please contact the instructor as soon as possible for accommodations.

The Honor Code

Academic conduct for students at Stanford is governed by the Honor Code. Part of the Honor Code is a pledge and expectation to participate in class without seeking inappropriate help on graded work such as assignments and exams. Please read the separate Honor Code page; you are responsible for knowing all of the details at this link, and for following the Honor Code in this course. Violations of the Honor Code are taken very seriously; we reserve the right to use software tools to compare your submissions against those of all other current and past students, and will refer all suspected violations to the Office of Community Standards.

Course Resources

Textbook

There is no required textbook for CS111: the material of the course is defined by the lectures and does not exactly correspond to any existing book. However, we recommend the following book if you would like an additional source of material to supplement lectures:

Operating Systems: Principles and Practice (2nd Edition), by Thomas Anderson and Michael Dahlin.

Each lecture lists related readings in this book on the first slide, where applicable. Most students find that the material from lecture is sufficient for their course needs, so we recommend that you start the course without the book and only purchase the book if you decide you would like additional material and explanations beyond what is in lecture.

Getting Help

We want to enable everyone to succeed in this course and offer several help resources. Read more about getting help in CS111.

  • Discussion Forum: The online discussion forum lets you search, ask and answer questions posted by fellow classmates. The course staff will also monitor and periodically respond to posts. The discussion forum is best for course policy questions, general course topic questions, general assignment questions or small debugging questions. It should not be used for larger questions about your assignment code.

  • Helper Hours: Helper hours are offered throughout the week, and are where you can sign up in a queue and get help from the course staff. Helper hours are best for course topic questions, general assignment questions, or in depth questions about your code. We will offer both remote and in-person helper hours; students who are ill, in COVID-19 isolation, have an emergency, or other exceptional circumstances may temporarily attend all helper hours remotely; please contact the instructor.

  • Instructor Email / Helper Hours: For private matters such as grade questions or other sensitive or confidential topics, please feel free to email the instructor directly or stop by their helper hours to talk privately.

  • The course website houses various useful documents, such as how-to guides for the tools, and advice pages. Please take advantage of these resources!

Other Information

COVID-19 Precautions

As of the start of the quarter, Stanford University is mandating the use of masks in classrooms, regardless of vaccination status. Please wear a mask in the lecture hall including when asking questions, during section, during helper hours, and during exams. If we see someone not wearing a mask, this is not necessarily a violation of the requirement. Some of us have health conditions precluding our ability to wear masks. Students in this situation should work with the Office of Accessible Education immediately, to receive an accommodation for a mask exemption. In addition, some of us might feel more comfortable wearing masks even when not required, such as when we are outdoors. Some of us might feel more comfortable social distancing even when not required, for example, during small-group work in lecture or section and while masked. All of our preferences are reasonable, and it is important that we treat each others’ preferences with respect and care. You can find the most current policies on campus masking requirements on the COVID-19 Health Alerts site, and you can consult the Campus Safety COVID Checklist for guidance.

Stanford Focus Listening System

Stanford Focus Listening System is available in our classroom! First, install the Mobile Connect app, available in the Apple App Store or Google Play. Then scan the posted QR code at the front of the classroom to access the direct audio feed with your headphones or hearing aids (connected to a phone). Additional information can be found at the Stanford Focus Listening System instructions.

Planning for the Unexpected

While this course has been designed as a primarily in-person course, we may need to pivot to a fully online course in the event of a campus closure. If that happens, we will notify you of this change via email and the course website. Our lectures will then move to a fully online format, along with helper hours and sections. Exams will be administered online. We will do our best to support you through the transition to online learning. For additional information and updates, check out the Start Safe Stay Safe Website: http://www.umsl.edu/staysafe/. Please be sure to sign up for emergency notifications from the University: https://safety.umsl.edu/police/notification/index.html.

Affordability of Course Materials

All students should retain receipts for books and other course-related expenses, as these may be qualified educational expenses for tax purposes. If you are an undergraduate receiving financial aid, you may be eligible for additional financial aid for required books and course materials if these expenses exceed the aid amount in your award letter. For more information, review your award letter or visit the Student Budget website. (https://financialaid.stanford.edu/undergrad/budget/index.html)

Lecture Video Notice

Video cameras located around the room will capture the instructor presentations in this course. For your convenience, you can access these recordings by logging into the course Canvas site. These recordings might be reused in other Stanford courses, viewed by other Stanford students, faculty, or staff, or used for other education and research purposes. Note that while the cameras are positioned with the primary goal of recording only the instructor, occasionally a part of your image or voice might be incidentally captured. If you have questions, please contact a member of the teaching team.