ECS150 Course Website

last updated
ECS150: Operating Systems

Welcome to the ECS150 Website for Winter 2004. You will be able to find all sorts of useful references and information here, especially regarding homework and labs. This site will be updated regularly, so please check it often.

If you have questions, comments, or suggestions regarding this website, please email


29 Mar 2004 Final grades have been posted! If you have any questions regarding your final grade, please contact Professor Levitt. I hope everyone had a great break, and I wish everyone the best of luck in the future!
22 Mar 2004 I updated some of the grades (mostly midterm regrades, and homework regrades). We should have the final grades posted by the end of this week.
16 Mar 2004 I added some information on the final exam (including information about a review session). You can find the info at
Dont forget to signup for a new interactive grading slot!!! (See previous announcements, lab 3 notes.) More groups have turned in labs than are signed up!
15 Mar 2004 Check the lab 3 notes for more help on lab 3!
14 Mar 2004 Someone was nice enough to point out that the original Tuesday office hours I previously posted are during lecture. So, I am going to hold office hours on Monday instead. I think Professor Levitt might hold a review session next week, so I am going to cancel my other office hours until I know when. Here are my revised office hours:
  • Monday March 15th 1:30pm - 3:30pm
That should give everyone a chance to ask questions about lab 3. When I know more about the *possible* review session, I'll post additional office hours to give everyone a chance to ask questions before the final.
12 Mar 2004 Homework 3 solutions have been posted. There will be an addendum later with the missing answers.
11 Mar 2004 Handin instructions for lab 3 have been posted.
10 Mar 2004 Update: I have some good news, and some bad news. The good news is that I am getting better. The bad news is that I have a followup doctor's appointment Friday at 1:30pm (there was not a lot of choice on time). This means that I will not be having office hours Friday. Next week, I'll have the following office hours:
  • Tuesday March 16th 6:00pm - 7:00pm
  • Wednesday March 17th 5:00pm - 7:00pm
  • Thursday March 18th 5:00pm - 7:00pm
09 Mar 2004 Discussion Canceled! No discussion Wednesday OR Friday!! I'm really sorry everyone. I won't be having office hours on Wednesday either. I think I might still be able to have office hours Friday (don't worry, I'll wear a mask). I'll keep everyone posted.
A few updates:
  1. Grades for homework 2 and lab 2 have been updated.
  2. Lab 3 has been posted. I just got the lab myself, so give me a couple days to post any hints and tips I can come up with.
  3. I am still very sick, and the doctor confirmed I am contagious. It is going to take me a little bit longer to respond to email, and you wont seem me around campus unless absolutely necessary. (I'd really hate to get someone else sick the last week of the quarter.)
08 Mar 2004 No office hours Monday (March 8th). Sorry everyone. I have been rather sick all weekend, so in the interest of my health (and yours) I am moving my office hours to Friday from 1:30pm to 3:30pm.
05 Mar 2004 Interactive grading signup sheets for lab 3 have been posted outside the Kemper Hall TA room.
04 Mar 2004 The extra homework 3 questions have been posted, and the due date for homework 3 is now Thursday, March 11, 2004 at 4:45PM
03 Mar 2004: Dr Levitt asked me to pass along the following message:

To ECS150,

I am feeling ill and will likely not be available for office hours tonight. Instead, I can stick around after class on Thurs. for as long as necessary.


I posted the notes I'll be using for this week's discussion.
02 Mar 2004: Okay, here is the deal on homework 2. Professor Levitt and I forgot to let the reader know that the homework due time was extended, so some homework was not picked up. I've already contacted Na (the reader) about the situation. I'll post an update when the rest of homework 2 has been graded.
You can download the midterm solutions here.
I have a few important announcements today:
  • PLEASE read directions. Specifically, the first line of the handout instructions for lab 2. You must demonstrate lab 2 on either the CSIF machines, or on your own personal laptop. I need to see the actual code modifications you made to give you a final grade for lab 2. So please do not expect to demonstrate your lab 2 on my laptop.
  • Interactive grading for lab 2 (this week) will most likely happen in one of the CSIF labs. (I've been having trouble finding space in the TA room to do grading.) I'll post a sign on the door when I'll be in one of the labs, but expect to have to look for me. (Finding space in the labs is also proving difficult.) Sorry!
  • There will be some changes to homework 3. First, there will be a couple problems added. Second, the due date will be pushed back to Thursday. I'll post another update when I have more specific information.
  • You'll have to signup for a different interactive grading slot for lab 3. Lab 3 interactive grading will be held on Tuesday March 16th, Wednesday March 17th, and Thursday March 18th. I'll post signup sheets later this week. Lab 3 will most likely be due Tuesday, March 16th (in the morning).
01 Mar 2004: Homework 2 grades have been posted.
Homework 3 has been posted. It is due 4:30pm Wednesday March 10th.
26 Feb 2004: Several clarifications have been posted in the lab 2 notes. Handin instructions have also been posted.
I will have office hours 4:00pm - 6:00pm Friday, February 27th (but not on Monday, March 1st).
Interactive grading for lab 2 will be held from Monday, March 1st to Friday, March 5th.
25 Feb 2004: Lab 2 has been extended to 10:00am Monday, March 1st.
24 Feb 2004: Midterm grades have been posted!
Added lab 2 notes.
21 Feb 2004: Update: Lab 2 is due Friday Feb 27th.
20 Feb 2004: I posted an initial version of lab 2. The only thing missing is the due date, and the handin procedure. That information will be posted later.
Posted discussion slides for this week and code snippets.
18 Feb 2004: Midterm Update: Semaphores and monitors will NOT be on the midterm. Low-level synchronization topics (like test and set, algorithms like Peterson's) WILL be on the midterm.
17 Feb 2004: Homework 2 solutions have been posted. Note: There are two versions of the solution, the original version and a formatted version. The formatted version might be a little bit easier to read.
13 Feb 2004: Dr Levitt asked me to pass along the following message:

The submission time for hw2 has been delayed until 3PM tues. We will post the solutions sometime after 3PM.

If you need to reach me (Karl Levitt) this weekend, send email with your question (if it is concise) and a telephone number so I can call you. I do not promise I will be in a position to call you, but I will try. It would help if you also let me know when you are available to receive my call.

At the beginning of Tuesday's lecture I will provide you with more detail on what topics the MT will cover.

I will NOT be holding office hours on President's Day (Monday, February 16th) since classes are not being held.
12 Feb 2004: Posted slides for this week's discussion sections.
10 Feb 2004: Grades for programming assignment #1 have been posted.
09 Feb 2004: I added information on "Recompiling the Kernel" and more "Hints and Tips" in the "Using Minix" section. This will be useful information for future programming assignments. I also added more common compile errors in the "Help / FAQ" section.
07 Feb 2004: Note: Homework 2 is due at 10:00am on Tueday Feb 17th.
06 Feb 2004: The scheduling notes have been placed in the "Lectures" section.
05 Feb 2004: Homework 2 has been posted in the "Homework" section.
04 Feb 2004: I posted the discussion slides I used today (and will use Friday). Please let me know if they are understandable (if not, I can try and make them more clear).
I took down the interactive grading signup sheets. If you still need to sign up for interactive grading, please email me directly!
03 Feb 2004: The solution for homework 1 can now be found in the "Homework" section. Thanks Na!
Homework 01 grades have been posted in the "Grades" section. Grades are indexed by the last four digits of your student ID number. If you can not find your ID, chances are we do not have it. Just email me at or stop by my office hours so I can update your information.
I am adding interactive grading slots on Tuesday from 4:45pm - 5:45pm. To signup for one of these slots, email me directly.
The midterm will (most likely) be held Thursday, February 19th.
01 Feb 2004: Monday, Feb 2nd I will have office hours from 3:15pm - 5:15pm. I'll have normal office hours Wednesday (1:30pm - 3:30pm). Sorry for the short notice!
Interactive grading starts this week on Thursday, Feb 5th and continues until the 10th! This means if you have a Monday slot, your interactive grading will be held on the 9th. I will send a reminder email the day before your grading session.
28 Jan 2004: You can download the notes I used in discussion here thanks to Dr Bishop.
Programming assignment #1 has been extended to Monday January 2nd. Therefore interactive grading will be held next week, starting Thursday. See the "Labs" section for more information.
Updated discussion information for this week. Added a couple of grading slots on Tuesdays.
27 Jan 2004: If you need problems 4, 5, and 6 for programming assignment #1, you can now find them in the "Labs" section. Just click the notes link for lab 1.
You can view the interactive grading time slots from the "Interactive Grading" section on the "Labs" page. (Note: The list is still complete. I'll update it as more people signup for interactive grading.)
You can find clarification on programming assignment #1 here.
26 Jan 2004: Please make sure you signup for an interactive grading timeslot by Thursday! Signup sheets are located outside Kemper Hall room 53.
23 Jan 2004: All quota issues should be resolved. If you added the course late and are still having problems contact
22 Jan 2004: FYI: The ECS150 homework box is in Kemper Hall room 83 (with the printers).
Some students may not be able to install Minix on the CSIF accounts due to quota issues. The problem is currently being worked on, and I'll let everyone know when it is fixed.
21 Jan 2004: Revamped the "Using Minix" and "Help/FAQ" sections. See those sections for material covered during Wednesday's discussion section and installation instructions for Bochs and Minix.
20 Jan 2004: Note: Since Monday classes are being held this Friday, there is no lecture this Friday. Please try and make the Wednesday discussion if possible. (I will post notes on the web if you can't make it.)
Posted first programming assignment in the "Labs" section. Also updated discussion schedule.
16 Jan 2004: Created "Lecture" section, and posted course notes from lecture 1. Posted printfile.c example used in discussion sections. Added link to book figures in "General Info" section.
14 Jan 2004: Syllabus (in General Info section) and homework 1 posted. Reader information updated.
13 Jan 2004: Launched course website.