Date: Tue, 10 Dec 1996 16:51:22 GMT Server: NCSA/1.4.2 Content-type: text/html Last-modified: Sat, 07 Dec 1996 00:41:32 GMT Content-length: 32694
Welcome to CSE/ENGR 142. We will use this page to make all sorts of announcements about the class, homework corrections and clarifications, etc. The newest messages are listed first. Check here often!
12/6/96
Old homework (through HW5) and the midterm exam should
be picked up from your TA as soon as possible if you haven't done
so already. We will not entertain questions on old homework grading
after classes end December 11 (it's already too late for midterm
questions). We'll announce later how we'll get HW6 back to you
(it may be at the final exam).
Audio in the IPL! Most of you have probably noticed the "Lecture Slides with Audio" link on our main page, and some of you report having used it at home. Viewing the slides while listening to the complete recorded lectures from last quarter might strike you as a fabulous and painless way to study for the final exam. We now have audio capability in the IPL. You can bring your own headset (an ordinary Walkman-type headset should work) and ask the lab monitor exactly where to plug it in. The Macs and some of the PCs in Suzallo Library are audio-ready, too. If you want to listen at home, there's complete information on the audio page about what is needed. Enjoy!
12/5/96
Section Q in the course packet ("Libraries, File I/O")
is incomplete; only one of the three original pages was reproduced.
Sorry. The missing pages can be found on the Web.
(Actually, it's likely we won't cover all of this material, anyway).
Holiday Hours
in the IPL.
The IPL will remain open normal hours through December 16. December
17 and 18 it may be partially closed for cleaning; after that
it will close and not reopen until Monday, January 6. Consultants
will be on full duty until 5:00 on Monday, December 9.
12/4/96
Computing survey results
have been tabulated for the 145 people who have responded so far.
Some of the comments are pretty fascinating (look for the one
about "eating oreos and drinking wine" as an advantage
of computing at home). If you haven't taken the survey yet, we
would really like you to -- why not take it now,
before reading your fellow students' responses, to keep from being
influenced by them.
11/27/96
Thanksgiving holiday hours for the IPL: closing at 5:00
pm Wednesday; closed all day Thursday and Friday; open 9-5 Saturday,
noon-midnight Sunday. Consultants may not be working their regularly
scheduled hours.
A copy of the problems from the recent ACM regional programming contest has been thumbtacked to the bulletin board outside the IPL. If you borrow it to study or copy, please return it promptly. So far, that particular problem set doesn't seem to be on-line anywhere. You can look at lots of problems from previous competitions on the ACM contest archive page. Practically all of them are solvable (in principle) with what you now know about C programming, except that they take their input from a file rather than from the keyboard.
11/26/96
There's been a problem printing hw6orig.c from within MSVC
-- the printing is cut off after about two pages. You can use
another program to print from (such as Notepad), or bring up the
"direct" copy of hw6orig.c from the HW6 page and print
from Netscape. We're looking at the problem and will post a new
archive if we can find a solution. Sorry once again for any inconvenience.
11/26/96
The PC archive for HW6 has been reenabled. The McAfee virus
checker found no infection. Nevertheless, use caution as always
when transferring files from one computer to another. If you have
virus checking software on your home computer (strongly recommended
anyway), you might wish to run it against your hard drive before
and after loading and unpacking the HW6 archive. Please report
any problems right away. And we are very sorry for the inconvenience.
The PC archive has been temporarily disabled due to suspicion
of a virus. We hope to have it back shortly. Meanwhile, remember
that you can study the hw6orig.c program and the detailed instructions
to help develop your design specification. The only thing you
can't do is run the demo.
11/26/96
Two of the comments in the HW6orig.c program are reversed.
In the function draw_world(), where it says /* draw horizontal
grid lines */ it should say /* draw vertical grid lines */ and
vice-versa.
11/25/96
Please help us by filling out a questionnaire on computing support. We would like to find out what we can do over the next quarter or so to improve computing support for this course, both for those using the programming lab and for those computing at home. The form is easy and fun to fill out and submit, so please do it now, or find a few minutes to do so sometime in the next few days.
11/25/96
As we announced in class this morning, the UW teams did spectacularly well in the ACM programming competition on Saturday. Thanks go to all of you for tolerating the loss of the IPL for the day. A special thanks to a couple of students in the course who worked as volunteers at the event. You can find their names, and lots more interesting information, at http://www.cs.washington.edu/homes/lazowska/acm/.
11/22/96
HW#6 is now available on the Web. Note that a piece
of it is due next Wednesday, November 27 (the date on the
in-class handout, November 21, was obviously wrong).
11/20/96
Clarification on HW#5: A comment buried in the code of
HW5orig.c suggests that the user should be able to press 0-9 on
the keyboard in order to change the message number. Please ignore
this comment; it was left over from an early version of the demo
program. You do not have provide this functionality in your program.
If you've already done so, it's OK to leave it in, however. Apologies
for any confusion.
11/19/96
HW#5 and Windows 3.1: In case you're running Windows 3.1
at home, we have a 16-bit executable version of the demo
which can be downloaded. However, it will probably run only if
you have Borland C++ installed. If you're using Windows 95 or
Windows NT, please don't even bother; if you are on Windows 3.1,
try it out and let us know if you encounter any problems.
11/19/96
More statistics from the midterm exam. 424 students took
the test. Perfect score was 72. Standard deviation was 12.7. There
were 6 72's (100%) and 12 71's. 112 students scored 65 (90%) or
above. The mean was 55.2 (77%). The median was 59 (82%); 210 students
were below the median and 206 were above. There were 74 scores
below 44 (60%).
11/18/96
The IPL will be unavailable on Saturday, November 23. It
will probably also be unavailable for the final hour of normal
open times on Friday, Nov. 22, i.e., unavailable from 5:00pm to
6:00pm. This is because the IPL will be the venue for the ACM
Programming Competition. If you're interesting in volunteering
to help out with the competition, talk to one of the instructors
or to professor Dan Weld (weld@cs.washington.edu). It would be
a great way to meet students from other universities who are also
interesting in computing. Other campus computing sites should
be open normal hours on those days.
HW#5 is now open for turn-in. Some changes have been made
to the software which we hope will result in overall faster processing.
If you notice any problems at all, please notify a consultant
right away or send e-mail to an instructor.
11/12/96
Fallout from the HW#4 turn-in debacle: Over 350 people
bravely overcame the obstacles and got HW#4 turned in by early
Saturday afternoon. We're sorry it was such a frustrating experience.
We've heard from a couple of people who because of holiday plans
had to leave campus before being able to do a successful turn-in.
If that was your situation, please send us a short e-mail
to that effect (it does not have to have a lengthy justification,
just a note as to your name, section, student number, and a brief
reason) and we will set up a special period when turnin for HW#4
will be open again. Meantime, the consultants will be asked not
to give any further help on HW#4. If you had already sent us e-mail
about the situation, please respond again anyway so that we're
sure your name will appear on the list of authorized people.
11/9/96
Notes on HW#5: GP142 is a Windows program; it requires a GUI (graphical user interface) environment, and will not run under DOS. It should be OK on Macintosh, although we have not completed our testing there. The demo program currently in the archive will run on Windows 95 or Windows NT only.
We are testing a Windows 3.1 version of the demo and will
put that in the archive later; it might require some further set-up
or helper files. Meanwhile, if you have Windows 3.1 at home, the
hw5orig.c program will probably compile, but we're not sure if
it will run properly unless you happen to have the Borland C++
version 4.5 compiler installed; in any case, you will need to
figure out how to create a project file or make file that pulls
together all the required files.
The turn-in form for HW#5 will not be enabled until all
the dust has cleared from HW#4.
11/8/96
A further reminder about the HW#4 lab report: please be sure
it is in plain ASCII format (see message from 11/6
below.) There is increasing suspicion that files in .doc or other
word processing formats may contribute to the slowdown problem.
They are also apparently one cause of the "document has no
data" error from Netscape.
Homework #4 deadline has been extended to noon, Saturday November 9; there will be no late penalty for work received by that time. Please put the turn-in receipts, stapled, in an envelope with your name and section on the outside, in the wooden box outside Sieg 128. If you complete turn-in off-campus but are unable to get back to campus to give us the form, please bring it on Tuesday.
We experienced several periods of web server outages or slowdowns on Friday. It may be that the large number of people trying simultaneously to turn in contributed to the problem -- investigation continues. The IPL closes at 6:30 pm on Friday and is supposed to open at 8:30 am Saturday. You can also use Netscape at Suzallo or at the ACC lab (Brooklyn & Pacific, open 24 hours a day). ACC has the Microsoft compiler installed but Suzallo does not. Some students printed copies of their programs and lab reports and put those in the box; you still need to do the electronic turn-in and give us the printed turn-in receipt.
Work turned in electronically after noon on Saturday will not
be accepted (unless further network problems necessitate a further
deadline extension, which would be announced on the Web.) It's
been a frustrating time for many of you; we appreciate your patience.
11/8/96
Sample solutions (.c files) for homeworks 2 and 3 are on
the Web, reachable from the corresponding homework pages.
Tabulations are not complete, but it appears the midterm exam
average score was about 55 (out of 72), with a standard deviation
of about 13.
11/7/96
Mac users have reported that the demo program does not behave
as described in situation of lab report question #3. As
noted a few days ago, we already know there are differences between
Windows 3.1 and Windows 95 versions of the demo in this area.
If you are using Macintosh or other platforms, differences are
possible. Treat the lab report the way you would a report in an
experimental science like biology or chemistry. That is, report
what you actually observed; if it's not what you expected, then
give a little background or context (such as the platform you
are running on, etc.) for the benefit of anyone reading your report.
11/6/96
1. hit "save as" in the file menu of Word
2. Change the file type to plain text.
3. save - you should have a plain ASCII file.
4. Turn in that file.
The midterm exam (with
and without answers) is now available.
There were 72 points possible. We'll try to have some statistics
for you by Friday.
More about IPL hours: beginning this Sunday (November 10),
the IPL will open at noon on Sundays rather than at 11:00 am.
11/5/96
The HW4 crunch is coming. The number of people who have
turned in HW4 is running way behind the number who had HW3 finished
at this point before the deadline. That means the IPL is going
to be super crowded between now and Friday. "All the computers
were busy" or "My computer had a problem that even the
consultant couldn't solve" will not be accepted as an excuse
for a late turn-in. So get in there now and avoid the last-minute
panic.
Veterans' Day Holiday IPL hours. We expect that the IPL
will be open normal hours this weekend and on Monday (Veterans'
Day), November 11. However, there may be limited technical and
consultant support.
10/30/96
If you are in section AA (Brown) or BE (Hong) only: To
relieve the crowding in our regular classroom, we have a small
overflow room for each exam period on Friday. It is large enough
to hold only the students in one section. If you are in section
AA: report directly to Sieg 225 for the 9:30 exam. If you
are in section BE: report directly to MEB 248 (Mechanical
Engineering) for the 11:30 exam. (If this is a hardship for any
reason, you can come to the regular room.)
Regardless of your section: when you come to the exam,
please know your section number and your student ID number; also
please carry your ID card with you. Also, please be on time; we
won't be able to give extra time to people who arrive late.
10/29/96
A new HW#4 PC archive is on the Web, and a new version
of the detailed instructions. Here's what's different. We found
on some systems, the demo program looped, and not on others. The
archive now has two executable demos, called demo16.exe (for DOS
and Windows 3.1), and demo32.exe (for Windows 95 and Windows NT).
For most of your investigations, either version, or the original
demo program called hw4demo.exe, will be the same. But for lab
report question #3, on the the demo32.exe version exhibits the
infinite loop behavior. So please use that version when you come
to question #3. Otherwise, everything is the same. Thanks to several
early-bird students for discovering this problem.
10/29/96
HW#4 lab report -- question #3. A couple of people have
reported that the demo program does NOT loop forever under the
conditions described in question #3. We're looking at this, and
right now we think it might be because the .exe was created for
Windows 3.1, whereas our own test version of it was compiled for
Win95. In any case: for now, please ignore question #3;
we'll come back to it another time. Question #4, on the other
hand, should be OK to proceed with; please note that it refers
to hw4orig.c, not the demo program.
10/29/96
Thanks for the comments on Homework #3. We read these comments
separated from the rest of the turn-in form, so they are effectively
anonymous. Naturally, we could find out who wrote what, but normally
don't. So that means if you have a question that you want answered
individually, as opposed to just a comment, please send it as
an e-mail or talk to us in office hours; or you could include
your e-mail address in the comment. In any case, the comments
are really valuable to give a sense of how we are doing as well
what some of your individual experiences and concerns are. Thanks
for taking the time and trouble to type them in.
10/29/96
All of the tips that we have mentioned before have been
collected into a single tips page.
You can get to it from here or from the main Web page. In addition
to previously announced tips on MSVC, there are some new tips
for Macintosh users.
10/28/96 (2:00 pm)
The complete HW#4 archive (for PCs) is now on the Web.
It is expected that the turn-in form for HW#4 will be enabled
later today, shortly after turn-in for HW#3 is closed. Nevertheless,
we encourage you to spend considerable time analyzing HW#4 before
starting to program.
10/28/96
HW#4 instructions and a skeletal .c program are now available
on the Web.
10/24/96
Is the 3-letter redisplay required? Yes. A couple of you
have pointed out that this enhancement was not listed as such
in the Detailed Instructions. But it was mentioned in a comment
in the program. So please go ahead and include it. What is the
purpose of it (aside from getting you to reuse some functions)?
The customer might have made several errors while typing in the
letters. The redisplay serves as a reminder and summary of what
has been ordered.
10/23/96
Vertical or horizontal? One of the enhancements in HW#3
is to redisplay the three letters chosen. There isn't any way,
using what we've studied so far, that you could display the three
letters horizontally across the screen. So they have to be displayed
vertically. On the other hand, you can and should find some (simple)
way to keep them from immediately disappearing off the top of
the screen.
Reminder: Midterm exam is Friday, November 1. A study guide
is now on the Web.
10/20/96
An error in a comment in the hw3orig.c program has been
pointed out. The function "sales-slip" has the comment
/*No calculations should be needed here, only printf's.*/
It turns out you do need to do one simple calculation (which could
in fact be embedded in a printf). In any case, don't repeat any
calculations which have already been made.
HW#3 is now open for turn-in.
Another tips file on working with workspaces in
MSVC++ is now available. If you have trouble with your disk filling
up, or get mysterious messages about needing a workspace or about
files not being in a workspace, take a few minutes and read through
this file. It may or may not solve your immediate problem, but
should give you some additional background for understanding the
situation.
10/18/96
HW#3 is now available. Locate it via the Homework page
from the course homepage.
A sample solution for HW#2 will be posted (on the HW#2
page) within a couple of days.
10/16/96
There are some new tips about
one method to keep your floppy disk from filling up. In
general, the more you know about MSVC and about Windows 95, the
more ways you can discover for yourself about ways to avoid problems
like this. Meantime, read this and the previous tips
as well.
The quote from today's lecture: "As soon as we started programming, we found to our surprise that it wasn't as easy to get programs right as we had thought. Debugging had to be discovered. I can remember the exact instant when I realized that a large part of my life from then on was going to be spent in finding mistakes in my own programs." Maurice Wilkes, British computer pioneer, 1949; quoted in Expert C Programming: Deep C Secrets by Peter van der Linden (Prentice Hall, 1994), p.109.
10/14/96
HW#2 turn-in form is now available on the Web. The Mac
version of HW#2 is now available to download. Please report
any problems with either via e-mail.
As mentioned below (10/11/96), you are likely to fill up your
diskette once you have created and run hw2b.c and hw2c.c.
Aside from starting with a blank high-density disk (single density
is definitely too small - ask for help if you are not sure if
your disk is formatted at the correct density), there are some
techniques for avoiding the problem. One is to copy your .c files
to a directory on the hard drive, and create a default project
there. The Windows Explorer can be used to create directories
and copy files. If you do this, be sure to copy your updated .c
files back to the floppy for safekeeping before restarting your
computer; all changes to the hard drive are automatically erased
when the machine restarts! We will try to post some details on
these suggestions later.
A different approach to the problem is to do what the .mdp
and .mak files provided on the archive do: they have settings
which instruct MSVC to place all the intermediate files on
a temporary directory on the hard drive, while allowing your
.c file to stay on the floppy. You could do this yourself by adjusting
the Settings on the Build menu. In any case, all the intermediate
files (.ilk, .pdb and many others) can safely be deleted from
your floppy; they are automatically rebuilt when needed.
How closely does your HW#2 solution have to follow the
samples? Well, your version should always give a correct answer
on valid, reasonable data. But if the input data types are wrong
(for example, typing a character when an integer is expected),
then the sample is not guaranteed to run correctly, and your program
doesn't need to, either. If the data type is right, but the values
are unexpected, then both programs should be able to handle it,
and in pretty much the same way. The exact wording of output is
not crucial as long as it is correct and appropriate. If you find
cases where our program seems to be wrong, please send mail with
particulars (i.e., give us the exact input values that produce
the bad answers.) If you're sure our program is not right for
a particular case, then you don't have to make yours do the same
wrong thing.
The final "hit any key to terminate the program"
or "hit any key to continue" are not essential parts
of the solution. They are only there to guarantee that the window
stays on the screen so that it can be read. When running from
within MSVC they aren't needed, but if you launch the program
from the Explorer they may be.
10/11/96
We've put a new version of the HW#2 archive on the Web.
If you're happy with the old one, there's no need to load the
new one. The new version has so-called "16-bit" executable
sample programs. These will run on Windows 3.1 as well as on Windows
95. They look slightly different - the background color is white
instead of black, and when the program finishes you have to close
the window by clicking on the close "X" in the upper
right-hand corner. We also corrected some minor details that various
of you had pointed out (thanks - and a commendation for getting
started so quickly!) None of these are important as far as how
your program works and how it's graded. What counts is getting
the right answers for good data and the right behavior for bad
data.
10/11/96
With Homework #2, there are some situations that can lead to your
A: disk being filled up. For one thing, using a fresh diskette
will help. Also, when working on hw2a.c, open the project by double-clicking
the .mdp file (as the instructions suggest), not the .c file.
We'll try to assemble some other tips for dealing with this.
10/11/96
The Homework #2 assignment is ready now. You can find it
on the Web. The distribution includes a couple of sample solutions,
in executable (.EXE) form. These exe's will run only on Windows
95 or Windows 95; they won't run on Windows 3.1.
Homework #1 is due today! You must have completed electronic
turn-in by 3:30. You must also turn in a (physical) copy of your
"receipt," stapled if it is more than one sheet.
If you haven't given it to your TA already, please bring it to
class today, or drop it in the box across the hall from Sieg 127.
Some brand-new tips on using MSVC
and the debugger are available. These were passed out during some
of the tutorials and were also distributed in class on Oct. 9.
10/9/96
Some students have asked where the MSVC "tips" are.
They are not in MSVC, but rather are files we created and posted
on the course Web. You can find the tips from the 142 home page.
10/8/96
Don't forget there will be tutorials today
(Tuesday) and Wednesday. Subject is MSVC.
10/7/96
The turn-in form for HW#1 is now ready to use. If you notice
problems, please let someone on the staff know as soon as possible.
Dr. Ladner will not hold office hours this Thursday (Oct.
10). You can still reach him via e-mail.
The IPL schedule this week is still a little up in the
air. We hope it will be open during the hours posted in the lab information
page, but in case it's not, please leave room for recovery, that
is, don't leave the homework until the last day. Do it now
if you haven't already.
10/4/96
The turn-in form for HW#1 has not been enabled yet. Apparently
a number of you have already reached that point in the homework
- that's great! We'll have the turn-in form enabled early next
week (it will be announced here, or check the HW#1 page).
10/3/96
Homework #1 is now on the Web. To do it, you'll need some
time and lots of patience (and a little magic).
It's due on Friday, October 11. Get started today! There will
be tutorials next week on Tuesday and Wednesday,
but don't wait until then.
10/2/96
Tutorials: At present, no more are scheduled for this week.
There should be several next Wednesday; keep checking the tutorials and special demos
page.
Lab hours: Some tentative hours for this week are Thursday
9-6; Fri 9-5, Sat 9-6; Sun 11-9. Also check the lab information
page.
10/1/96
A new page has been set up with information about tutorials and special demos.
Several more are planned for this week and next.
Instructor office hours corrections and change. The office
hours for Dickey & Ladner were switched on the original printed
Syllabus handout. Dickey has also made a change in Friday office
hours. Apologies to anyone who may have stopped by and not found
one of us in our office at the announced times. The corrected
times are now on the Syllabus page and on the Staff page. For
reference, here they are again: Dickey: M & W, 1:30-2:30;
F 2:30-3:30. Ladner: Tu & Th 10:30am-noon. TA times will be
posted later this week on the Staff page.