Randal E. Bryant and David R. O'Hallaron
School of Computer Science
Carnegie Mellon University
Our aim in CS 213 is to help you become a better programmer by teaching you the basic concepts underlying all computer systems. We want you to learn what really happens when your programs run, so that when things go wrong (as they always do) you will have the intellectual tools to solve the problem.
Why do you need to understand computer systems if you do all of your programming in high level languages? In most of computer science, we're pushed to make abstractions and stay within their frameworks. But, any abstraction ignores effects that can become critical. As an analogy, Newtonian mechanics ignores relativistic effects. The Newtonian abstraction is completely appropriate for bodies moving at less than 0.1c, but higher speeds require working at a greater level of detail.
Our 21X sequence works as follows: 211 is based on a simplified model of program execution. 212 builds further layers of abstraction. 213 introduces greater detail about system behavior and operation. This greater detail is needed for optimizing program performance, for working within the finite memory and word size constraints of computers, and for systems-level programming.
The following "realities" are some of the major areas where the abstractions we teach in 211/212 break down:
This is a totally new course for which no complete textbook exists In fact, your instructors will probably end up having to write it! In the interim, the following will serve as the text for the course:
Brian W. Kernighan and Dennis M. Ritchie, The C Programming Language, Second Edition, Prentice Hall, 1988.This the classic K & R book, the standard against which all reference manuals are compared. Although it only provides partial coverage of the course material, it is an essential part of every computer scientist's library.
Your participation in the course will involve five forms of activity:
Attendance will not be taken at the lectures or recitation sections. You will be considered responsible for all material presented at the lectures and recitations. Lectures will cover higher-level concepts. Recitations will be more applied, covering important ``how-to's'', especially in using tools that will help you do the labs. In addition, the recitations will help clarify lecture topics and describe exam coverage.
There will be two types of assignments in this class. Lab assignments will be multi-week efforts providing in-depth understanding of some aspect of computer systems. Labs will involve some combination of C and assembly programming, and some will involve performance measurements. Homework assignments will 1-week efforts that involve solving a series of smaller problems. The solution to many of these will involve writing small C programs.
For urgent communication with the teaching staff, it is best to send electronic mail (preferred) or to phone.
If you want to talk to a staff member in person, remember that our posted office hours are merely times when we guarantee that we will be in our offices. You are always welcome to visit us outside of office hours if you need help or want to talk about the course. However, we ask that you follow a few simple guidelines:
Using the Web, you can:
We have also set up a news group for this class, cmu.cs.class.cs213. This group will be used by members of the teaching staff to post announcements and clarifications. You may also post to this group to make queries.
For both homeworks and labs, you may work in groups of up to 2 people. It is up to you to form and regulate your own groups. If you are not happy with your partner, you are free to find another partner. You may also work by yourself.
All assignments are due at 12:01am (one minute past midnight) on the specified due date. All handins are electronic, usually consisting of one or more files that are to be copied to a specified directory. The writeup for an assignments will provide about the handin procedure for that assignment.
Late assignments will be docked 20% each day for the first two days. Assignments more than 2 days late will not be accepted, unless you have arranged for an extension in advance with your instructors. For example, suppose an assignment is due at 12:01am on Thursday. If you hand it in between 12:02am Thursday and 12:01am Friday, you will be docked 20%. If you turn it in between 12:02am Friday and 12:01am Saturday, you will be docked 40%. You won't be able to turn it in at all after 12:01am Saturday.
Missed exams and assignments more than 2 days late can be made up, but only if you make prior arrangements with Prof. O'Hallaron. However you should have a good reason for doing so. It is your responsibility to get your assignments done on time. Be sure to work far enough in advance to avoid unexpected problems, such as illness, unreliable or overloaded computer systems, etc.
After each exam, homework, and assignment is graded, Prof. O'Hallaron will send each of you a personalized email with your grade (as well as all of your previous grades). You have seven calendar days from the date he sends the email to appeal your grade.
If you have questions about the grade you received on an assignment (homework or lab), please talk first to the person in charge of the assignment, who will be clearly identified in the writeup. If you are still not satisfied, please come and visit Prof. O'Hallaron.
If you have questions about an exam grade, please visit Prof. O'Hallaron directly.
Each student will receive a numeric score for the course, based on a weighted average of the following:
Grades for the course will be determined by a curve. The total score will be plotted as a histogram, and then approximate cutoff points for the different letter grades will be determined. Individual cases, especially those near the cutoff points may be adjusted upward or downward based on factors such as attendance, class participation, improvement throught the course, final exam performance, and special circumstances.
All of your assignments allow collaboration, but only with the other member of your project group. Each assignment must be the sole work of the group turning it in. Assignments will be closely monitored, and students may be asked to explain any suspicious similarities. The following are guidelines on what collaboration outside of your group is authorized and what is not:
What is Cheating?
What is NOT Cheating?
Be sure to store your work in protected directories.
The penalty for cheating will depend on the severity of the offense and the student's past record in this regard. At the very least the student will be given a score of 0 for the assignment.
We will use a cluster of Alphas for the labs and assignments. The class Web page has details.
Figure 1 shows the tentative schedule for the class. The notation ``Hi'' indicates a homework assignment, while ``Li'' indicates a lab. Any changes will be announced on the class news group. An updated schedule will be maintained on the class web page.
Figure 1: Tentative Class Schedule