CMSC216: Introduction to Computer Systems

Introduction to the interaction between user programs and the operating system/hardware. Major topics include C programming, introductory systems programming, and assembly language. Other concepts covered include UNIX, machine data representation, thread management, optimization, and virtual memory. Programming is done in the Linux Environment.

Minimum grade of C- in CMSC132; and minimum grade of C- in MATH141.

It is presumed that students will have the equivalent of 1 year of college-level programming in some high-level language such as Java or Python prior to taking this course. The C programming language will be introduced but not at an introductory level so prior programming experience is a must.

Students that complete CMSC216 will posses the following characteristics.

• Basic proficiency at C programming including pointers and addressing, dynamic memory allocation and management, basic file I/O operations. Ability to edit, compile, run, and debug C programs.
• Knowledge of running programs in physical memory including the stack, heap, global, and text areas of memory and how each area behaves. Basic understanding of security risks associated with programming errors related to memory such as buffer overflows.
• Understanding of the essential elements of assembly languages executed by CPUs, specifically familiarity with the x86-64 assembly language
• Knowledge of the correspondence between high-level program constructs and assembly instructions which are executed by the CPU.
• Ability to use a symbolic debugger to step through both C programs and assembly programs to aid in debugging programs.
• Basic understanding of how data is encoded in binary including signed and unsigned integers, floating point numbers, character data, and machine instructions
• Knowledge of computer memory systems, particularly the memory hierarchy of registers, caches, main memory, and permanent storage.
• Understand the Process abstraction of running programs, how it allows isolation and safety between programs, and the ability to create and manipulate processes programmatically.
• Knowledge of execution Threads, their relation to processes, and the ability to create and manipulate them programmatically.

Office hours are held by staff members at various times outside of lecture and discussion.

• Times and Locations of office hours will be posted on the course Canvas site. Most TAs hold office hours in a common location while Professors usually hold office hours in their office and some staff hold office hours online.
• Office hours are open to all students without appointments.
• Students are strongly encouraged to visit the professor and teaching assistant(s) during office hours to further their understanding of the material: we are here to help you learn.
• Students at office hours are helped on a first-come first-serve basis. As things get busy, a whiteboard may be used for students to "queue" to get help from staff.
• Often office hours will become crowded around project deadlines. Students are advised to start projects early, come to office hours with questions prepared, and be patient. Set your expectations accordingly: last-minute help is often in short supply.
• When office hours are crowded, staff members will typically spend around 10 minutes helping a student before moving to the next queued student. Staff can make more progress with students if they are prepared to receive help by having specific questions they want to discuss and having their environment set up to address those problems (code editor up, programs compiled, analysis of test case failures available, etc.).
• Staff will NOT do assignments for students in office hours. If staff members feel students are relying too heavily on staff input to complete required work, they will ask students to try the work on their own and form specific questions around it before offering further help. The goal of this and any course is for student to develop their own capability. Students should expect to toil some while pursuing that goal.

This offering of the course will be administered in a mixture of in-person + online which means you should acquaint yourself with the following resources / policies on communication in the class.

• ELMS/Canvas (Course Management): used to provide links to other resources and for Overall grade dissemination
• Gradescope (Assignments/Exams): used to submit most graded work, receive grades on that work, and make requests for regrades.
• Piazza (Announcements/Async Q&A): used to ask questions on course material outside of synchronous meetings and for staff to make announcements to students.
• Zoom (Video Conferencing): used to present audio/video synchronously such as for individual online appointments or online office hours.
• Email: Asynchronous inquiry with staff about personal matters such as illness or emergencies.

Here are common situations for students and the best method to use to contact staff.

• I'm going to miss a lecture / discussion meeting. What should I do?

  No special action is required if you'll miss a standard lecture or discussion: attendance is optional but encouraged. All lectures will be recorded and will be viewable within two days of them happening to support the inevitable conflicts that arise. Discussions have online materials and are designed to allow students to work through them independently if needed or to collaborate on with a friend in the course.

• I want to get real-time assistance with some coursework.

  Stop by office hours online or in preson. Locations and times for office hours are listed on the course Canvas site. Keep in mind that office hours get busy around project deadlines so there may be a queue to wait in to get help.

• I have a question on an assignment or course content and there aren't any office hours coming up soon.

  Post your question on Piazza; staff members check several times a day and answer questions there. Make sure to post an answerable question as described in the Etiquette Piazza post and avoid publicly posting large portions of your code.

  You might also try searching Piazza first to see if someone already asked your question and received an answer.

• I have a logistics questions such as when something is due, when something will happen, etc.

  Also use Piazza for most of these. If a staff member isn't sure how to answer the question, they'll give you they're best guess sooner and ask the Professor to confirm later.

  Staff will often use Piazza for Announcements such as for upcoming deadlines or canceled office hours. These announcements will go to student email so check your UMN account regularly.

• I made a Piazza post but no one seems to be answering it. What gives?

  Make your post either "Public" (viewable by anyone) ore "Instructors Only" (private). DO NOT select individual staff members for visibility: if you select only Prof. Kauffman to view your post, it probably won't get viewed as TAs won't be able to see it and notify him it needs attention. Email Prof Kauffman directly for private matters such as health or concerns about grades (but not about project questions).

• I think some of my work was graded wrong and I want someone to look at it again.

  Gradescope has a "Request Regrade" feature which will be open for students to use after grades are posted. Using this feature will notify whoever graded your work to have another look. If you cannot resolve the issue, your grader will involve the professor. Regrades will accepted for about a week after grades are released and will then close so make sure to check your grading during that window.

  Some assignments don't allow for regrades as they are structured around repeated attempts to get full credit:

  • Homework Quizzes allow you to retake the Quiz to improve your score. No online Regrade Requests will be available, just retake the quiz up to the deadline.
  • Lab Exercises can re-submitted as many times as you like prior to their deadline and give nearly immediate feedback. If you aren't getting full credit and can't figure out why, get help from staff and then resubmit.

• I need some one-on-one help and I can't make it to office hours to talk to staff about it.

  Email one or two of your favorite staff members to see if they can meet outside of their normal office hours. If you don't have luck in the first go, try contacting a different staff member including Prof. Kauffman.

• I had a major life event (got sick / family emergency / mental health problem) and I'm wondering how to cope with it and this class.

  Email Prof. Kauffman as soon as you can. Explain the situation and we'll work out a plan for how to proceed such as rescheduling exams, extending deadlines, or providing some additional help

This is an in-person course but many elements of the course can be completed without physical attendance. Fully remote students are not supported in this class as all students must attend exams in person.

Below is a summary of course elements and their particulars.

Final grades will be determined by scores obtained on the components below according to their associated weight.

Final grades will be assigned without rounding according to the following criteria.

If circumstances require it, the grading scale may be adjusted, generally in the students' favor, though this has never occurred in any past semester.

Throughout the semester, students will have opportunities to earn Engagement Points (EPs) which are the "bonus credit" currency in the course. These reflect attention and effort devoted to the course to show engagement with learning content. Opportunities to EPs are roughly:

• Asking and answering question during lecture
• Answering questions on our discussion board and receiving endorsements from staff
• Participating on certain days during discussion sections
• Taking course surveys to give feedback to staff when they are on offer
• Submitting projects on time; late submission earns no EPs

At the end of the semester, students will earn a bonus to their overall grade based on the number of EPs they accumulate according to the following formula:

Bonus = 0.50% * floor(log2(TotalEPs + 1))

Staff reserve the right to adjust this formula in the event that it skews the overall grade distribution in unanticipated ways. Any such changes will be publicly announced.

FAQ: How many Engagment Points do I have? No running total of EPs will be kept by staff. The final tabulation will be done at the end of the semester. Students may estimate their own total EPs by checking the participation sheets in lecture, counting their discussion board answers and endorsements, adding on the surveys they've taken and discussion participation they've earned, and calculating the EPs earned from submitting projects on time.

Lectures will be delivered in person at the times/locations mentioned in the course schedule. During lectures, students will frequently be asked to work on short exercises with a few of their colleagues. After working on these exercises, the Professor will select a 1-2 students from the "Hot Seats" section of the lecture hall to discuss their answers with the class. Showing effort on these exercises will earn Engagement Points. Hot Seats locations will be announced at the beginning of the course and are typically the first few rows of a lecture hall or a few designated tables in an active classroom.

All lectures will be recorded and posted for asynchronous viewing within 48 hours of the meeting. Students not able to attend lecture synchronously will miss the chance to ask questions and earn Engagement Points for bonus credit.

In the event that the instructor is ill or the University deems the it is too risky to conduct in-person meetings, Lectures will be held in a similar format online via Zoom. Updates on any such changes will be announced to students through Piazza and Email.

Discussion sections meet twice per week in the locations mentioned. During these meetings, various activities will be conducted to aid students in assimilating course content such as:

• Discussing part of the week's Lab exercise and showing how to solve it
• Discussing a portions of a programming project and aiding students in addressing the requirements
• Presenting a problem related to recent lecture to give students additional practice
• Covering practice exams to prepare for an actual exam
• Conducting a review game in preparation for exams

Attending their registered discussion sections is strongly encouraged for all students but it is not required. Attending some discussion meetings will earn Engagement Points but these will not be announced in advance.

Each week a Lab exercise will be assigned for students to complete. Lab exercises will problems that relate to topics from lecture and usually demonstrate functions or techniques required to complete the large projects. Labs are evaluated using automated means and are submitted online for credit when complete.

No late submissions will be accepted for Lab Exercises. Deadlines to submit labs are typically at the end of the week they are assigned. The lowest two lab grades will be dropped when calculating the lab contribution to a student's overall grade.

Each week a set of Homework exercises will be posted online which reinforce and apply lecture topics. These are optional practice and will not be graded. Students wanting for more practice including exam-style questions should turn their attention to this homework. Students asking for more sample problems to work on will first be asked to show their own solutions to homework before any staff effort is devoted to deriving new problems.

Students will receive a number of programming projects during the semester. Each project will involve writing programs and answering questions about them to illustrate an understanding of course material. Projects are usually large and require a significant amount of work to complete. Working on larger projects will teach students new skills that cannot be covered when coding can be completed in a single short sitting. Most students benefit from starting projects early so that they have time to address the requirements over several days and receive help from staff when obstacles are discovered.

Project grading will include the following elements.

1. Manual Inspection: Projects will include a checklist of features of completely correct answers. These usually comprise things that cannot be easily checked automatically such as showing the process to reach an answer, inclusion of key elements of an answer, or style aspects of computer code. These features will be checked by graders and assigned credit based on level of compliance.
2. Automatic Testing: Most projects have automatic tests provided which check for correctly functioning programs or answers. In most cases, these automatic checks will be publicly available for use while working on the assignment.

Late submission of Projects is governed by the following table of policies.

No projects will be accepted more than 48 hours after a deadline.

Students are free to submit their projects as many times as they wish up to the Submission Close. Once Submission Closes, the most recently submitted submission will be graded unless students select a different submission for grading.

There will be a series of midterm exams during the semester and a comprehensive final exam at the end of the semester. Midterm Exams take place during the regularly scheduled lecture period and are worth a significant portion of the overall course grade. Dates for exams appear on the course schedule at the beginning of the semester.

All exams will be preceded by official Practice Exams so that students can acquaint themselves with the tools and tactics to be successful. Students are not allowed to share or receive exams from past semesters.

Missing an exam results in a zero score and make-up exams will be considered only in situations involving significant life events. Proof of such circumstances will be required for a make-up to be considered.

Most coursework will be graded via Gradescope which features a Request Regrade Button associated with specific problems and criteria. This will notify the specific individual responsible grading about the dispute. Raise regrade requests respectfully and specifically: mention what you think a grader missed in your answer or why you feel a deduction was unfair. Keep in mind that graders assign credit based on what appears on the project and exams, not post-hoc explanations of answers.

If a Student and Grader are not able to resolve a grading issue to the satisfaction of both, the student can ask the grader to consult the Professor who will review the dispute and resolve it. Students should ask their grader to do this, not email the Professor directly.

When grades are published, there will generally be a 1 week window in which disputes are considered. Failing to request a regrade in that time will forfeit further opportunity to contest the grade.

The deadlines for assignments will be included in the assignments as they are released. Generally HWs and Labs will be due weekly and Projects will run 8-12 days with deadlines listed on the course schedule. Exam Dates will also be listed on the course schedule.

The course schedule is here: schedule.html

Readings from the textbook relevant to each lecture are listed in the schedule. You will increase your understanding of lectures by reading associated textbook sections ahead of time, though this is not assumed. We may provide additional reading material to supplement the textbook which will be posted on the course web page.

At-home assignments (projects, labs, HWs) may be done via Free Collaboration: any resources may be utilized and students may freely collaborate on them. Below are specific guidelines for these items.

Students are free to use any resources they would like while constructing solutions to at-home assignment (Projects, Labs, and Homework). This includes the following which are allowed:

• Students may work together in groups to complete out-of-class work, share code, compare answers, assist one another in debugging, and learn together. This is true on Projects, Labs, and Homework exercises.
• Students may consult solutions they find online constructed by others and utilize them while constructing their own solutions.
• Students may utilize LLMs, Chat Bots, and other AI tools while constructing solutions.

Students will not be penalized for doing any of the above unless they are asked to explain their submitted work and cannot do so. In those cases, students will have credit removed from the corresponding component of the assignment. Situations in which students may be asked to explain their work may arise due to submitting unusual solutions that use inappropriate functions or techniques not covered in the course.

Certain assignments (projects) will include a "Work Disclosure" in which students describe how they constructed their solutions, who was involved, and what sources were utilized. This is a reflective exercise to enable students to understand how heavily they relied outside sources versus how well they can stand on their own for future solutions.

The goal of this course and most others is for students to improve their understanding of topics and become more capable. While most problems in the course are oriented towards beginners with many existing solutions readily available, students should still strive to solve these problems without aid from outside collaborators, human or artificial. By practicing these problems in earnest, students will build the ability to handle more complex solutions in the future that do not have well-established answers.

Students are strongly advised to do the following to maximize their learning,

1. Attempt to construct programming solutions and answers on their own before consulting collaborators.
2. Ask for help form course staff when they struggle to solve a problem. Staff are hear to help and are best equipped to guide students towards solution mechanisms appropriate to assignments.
3. Practice explaining their solutions to each other and to course staff. This is a great way to solidify ownership of solutions and prepare for exams.
4. Disable LLM/AI/Chat tools in their programming environment to prevent code from being prematurely proffered by such tools.
5. If faced with code or solutions that they do not understand, investigate these, achieve mastery of them or discard them and adopt solution mechanisms presented in course material.
6. Do not give away code solutions to others. Do not ask for code solutions when you have none your own. Collaborate on answers by building them together OR building them separately and then discussing together.

Generally there is high correlation with students who do all of the above and the following:

• Be able to explain their work if asked to do so
• Achieve good success on exams in the class
• Become a productive team member due to individual prowess at a job

Course staff will post solutions to some but not all of the out-of-class assignments in the course.

Students may NOT post their solutions to any coursework in public areas such as Github, class forums, or other websites. If students wish to share code they write for the course such as with potential employers, they are advised to create private code repositories and add specific others as collaborators to enable viewing.

Exam solutions will not be posted and students may not share their exams publicly or nor share them privately with students outside of this semester's cohort.

Exams are where students prove their individual mastery of course content. Students may be asked to explain the exam solutions in more detail and inability to do so will be construed as evidence of misconduct.

In particular, the following activities concerning exams constitute academic violations:

• Using, sharing, or receiving exam materials from another student from past offerings of this course; you may only view your own past copies of exams. Sharing exam material with future students is also forbidden. All students will be given access to the same practice materials pertinent to this semester. Not everyone has a friend from last semester to share exams with them and doing so creates a hugely unfair situation.
• Sharing the contents of a present semester's exam with others in the event a student has permission to take the exam earlier or later than the usual exam time.
• Posting your exam publicly anywhere or sharing it in a public fashion.
• Copying another student's answer during an exam.
• Using an LLM, AI too, internet search, arbitrary unauthorized website, or other out-of-bounds resource during an exam. Students are urged to disable an LLM / AI / Chat tool in their programming environment to aid their learning and prevent exam violations.
• Submitting code or solutions one cannot explain fully. Example: Teej used AI to complete a project and utilizes part of that code during an exam but cannot explain some of the functions in it; this is academic misconduct.
• Paying someone for a solutions to exams.
• Communicating with anyone except course staff during an exam; email, chat applications, discussion boards, texting, and all other communication is forbidden.
• Aiding or abetting any of the above.
• Witnessing any of the above and failing to report it to an instructor immediately.

All Of This Has Happened Before And Will Happen Again. Don't become one of your Professor's stories.

All exams are Open Resource Exams in which many of the resources students have accumulated may be utilized. Open Resource is NOT Free Collaboration and students should take care to understand the difference so that they abide by exam rules. Below are a specific guidelines on what can and cannot be used during an exam.

Students will have an opportunity in lecture to ask about these regulations to understand the boundaries more thoroughly.

Any instance of misconduct that is detected will investigated and may be referred to the Office of Student Conduct (OSC). The most common penalty is an XF in the course (failure due to academic integrity).

Refer to the following links for additional information.

• UMD Student Conduct Code
• Computer Science Department policies on scholastic dishonesty
• Office of Student Conduct which handles academic integrity violations

These policies only govern the listed sections of this course and it is not coordinate with other sections. Coursework and exams will differ between sections along with the overarching schedule. The policies within this syllabus apply only to our section and students should refrain from collaborating outside of their own section to avoid problems. TAs for different sections will not be able to provide specific assistance on assignments to students from other sections though may be able to assist with general course concepts.

Students are expected to maintain a high level of civility for all participants in and out of class meetings. This includes respecting participants of all genders, ethnicities, and social backgrounds. Harassment of any type will not be tolerated and failure to behave in a respectful manner will be reported to the Office of Student Conduct.

Observance of religious events will be accommodated for students of any faith. If a religious event will interfere with completing coursework, contact the instructor to discuss accommodations.

Students with disabilities will be provided accommodations listed in letters from Accessibility & Disability Services office. Students who feel they need an accommodation of this sort should contact that office to obtain a letter and provide it to the instructor as soon as possible, ideally as the semester begins.

This course will include video and audio recordings of class lectures and classroom activities. These recordings will be used for educational purposes and the instructor will make these available to students currently enrolled in this course. Students must seek instructor permission in order to share either course recordings or course content/materials. Similarly, instructors who wish to share zoom recordings with other sections or classes must seek and document permission from students whose image or voice are in these recordings.

If you have an issue that arises with a student or TA in this class, please contact your course instructor first via Email.

If you are uncomfortable contacting your instructor or if issues are not addressed to your satisfaction, please report the issus the to the Computer Science Department via its Class Concern Form: https://www.cs.umd.edu/classconcern