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Welcome to the website for Computer Systems Fundamentals (Fall 2025) at Johns Hopkins University!

The course is about computer systems from the programmer’s perspective. We’ll be making a fairly deep dive into topics such as data representation, memory, assembly language, CPU architecture, networks, and concurrency. By the end of the course you’ll know a lot about how modern computers really work and how to take advantage of their advanced features.

All public information about the course (readings, assignments, etc.) will be posted on this website.

Use the links above to navigate the site. The Syllabus describes course policies. The Schedule is the schedule of readings and exams. The Assignments page has links to the programming assignments and indicates when they are due. The Resources page has links to useful resources.

Important links

• Courselore (ask questions here!): https://courselore.org/

Please email daveho@cs.jhu.edu if you need to get access to Courselore.

News

• Oct 21 — Exam 2 will take place in class on Monday, November 3rd. Review materials are available on the Resources page. A review session will be held in class on Friday, Oct 31st.
• Oct 6 — Assignment 3, has three milestones, due Friday, Oct 10th, Friday, Oct 24th, and Friday, Oct 31st, respectively. Note that no late hours may be used on MS1, and at most 48 late hours may be used on MS2.
• Sep 25 — Assignment 2 has been updated so that the evaluation of the quality and comprehensiveness of your unit tests (for your helper functions) will happen in Milestone 3, not Milestone 2.
• Sep 10 — Assignment 2 has three milestones, due Friday, Sep 19th, Friday, Sep 26th, and Friday, Oct 3rd, respectively.
• Sep 4 — Some clarifications regarding fixpoint_add, fixpoint_sub, and fixpoint_mul have been added to the specifications for Assignment 1.
• Aug 25 — Assignment 1 has two milestones, due Wednesday, Sep 3rd, and Wednesday, Sep 10th, respectively.
• Aug 17 — Welcome back! You will need an iClicker remote in order to participate in in-class peer instruction activities. You have two options:
  1. Borrow one: fill out the form at https://forms.gle/4WPK5MieVZujTyjR9 and pick up an iClicker either Friday, Aug 22nd, 1–3 pm, outside Malone Hall (under the colonnade connecting to Mason Hall), or Monday, Aug 25th, 8-8:30 am, Hodson second floor lobby.
  2. Use your own: fill out the form at https://forms.gle/fZzYRurip8jWyH768 to register your iClicker’s remote id (so we can connect your poll responses to your participation grade.)