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Physics 3730/6720 Your First Lab Session
Fall Semester 2018
These instructions are intended for students who are using the
computer lab for the first time.
If you didn't already have a Physics computer account before you
enrolled in this class, you should have received a sheet of paper with
your username and password. Students who registered late may have
been missed. Please see the instructor if you don't have your account
Selecting the Lab Server
We use terminals in the computer lab. They are are supported by three
large servers elsewhere in the building. The ones for our course are
called "cygnus", "orion", and "draco". You should find them in the
icons on the left of your screen. Double-click on one of them. You
should then get a login banner for that server.
Note that the server will save your session unless you log off. It is
saved if you kill the desktop window (the X at the top right). When
you log in to the same server, you should find your session. If you
log into a different server, you won't. So if you want to keep your
session going in this way, please remember the one you chose. Also,
please be sure all your work is saved to a file before leaving your
Type in your username, hit enter, and then type in your password when
prompted. Unix is case-sensitive, so be careful to use upper and lower
case exactly as given.
Starting a terminal window
If you don't already have a terminal window, move the cursor to an
empty place on the desktop, and with the right mouse button, pull down
a menu and select "Open in terminal". You should get a terminal window.
Change your password immediately
If this is the first time you have logged in, you will be asked to
change your password immediately. This is important. Do this in the
terminal window. If you aren't already being asked to change it, type in
the command passwd to do it. You will first be asked for your
current password. Then you will be asked twice to enter the new one.
Your password is a string of letters, numbers, and/or special
characters that you can remember easily but others would find it
difficult to guess. Unix distinguishes upper and lowercase
letters. For the sake of security on this system, we urge you to
choose your password wisely. Don't use names and words found in
dictionaries or any personal information others are likely to know. A
combination of letters and numbers, upper and lowercase and/or special
characters is good. Your password should contain at least six
characters. For example, you could create a password from the first
letters of a mnemonic phrase, such as ``TatDyrlf!'' for ``These aren't
the Droids you are looking for!''. (But don't use this one, now! Make up
The Applications menu
On the menu bar at the top of the screen you should see an
"Applications" pull-down menu. It takes you to the web browser,
e-mail, and various applications.
Firefox web browser
We use Firefox. Starting from the "Applications" menu at the top left,
select "Internet" -> "Firefox"
Typing in a Terminal Window
The command interpreter is called the shell. The terminal
window is the basic interface for communicating with the shell. Any
command or other information you type will not be interpreted until
you hit <Enter>. Before that, you may hit <Backspace> to redo the
previous character. To redo the entire command from the beginning,
hold down the <Ctrl> key while typing u. (This operation is
abbreviated C-u in the class notes.)
Bottom Terminal Bar
The bottom terminal bar has tabs for each open window. Click on the
tab for a window to toggle between bringing it to the front and hiding
Notice that the bottom terminal bar has a several rectangles on the
right. These are for selecting different desktops, should you decide
to organize your session this way. Click to switch to another desktop.
You can also use the mouse to drag windows between desktops.
Systems menu and logging out
From the menu bar at the top of the screen, go to the System menu.
Select "Log out ...".
Please do not lock your screen unless you are just taking a quick
bathroom break. The terminals are shared by everyone. Locked
sessions will be killed by the administration with no guarantees that
your work is saved.
This page is maintained by:
Carleton DeTar Physics 3730/6720 Instructor
Last modified: 12 August 2018