This reading is also available in PDF.
Summary: We examine the operating system environment in
which the course is conducted.
Contents:
As this is a workshop-style course (aka a constructivist, collaborative
computing course
), you will be working on the computers in our
classroom on most class days. You will quickly find that these computers
have many similarities to the computers you have used in the past,
but that there are also some differences. (When we started teaching
this course, many students hadn't used computers at all. You will
occasionally find comments in the readings and labs that reflect that
different perspective.) In this document, we will explore some of the
key issues you may need to consider in working in the MathLAN.
A modern computer is much more than a bunch of circuitry. Most of us think
of computers in terms of the operating system that they run and
the graphical user interface that accompanies the operating system.
Those terms may be new to you, so let us consider them quickly.
As its name suggests, an operating system (also OS
) is the system
used for operating the computer. It is a large computer program that
manages and simplifies most of the underlying hardware. The operating
system is responsible for managing files, managing other programs, dealing
with the keyboard, screen, and other peripherals, and much more.
In the old days of computing (e.g., when I started), you interacted with
the operating systems almost exclusively by typing on a keyboard and
seeing results on a screen (yes, we had evolved beyond punchcards).
There was no mouse. To us, the operating system really referred to the
underlying capabilities.
These days, you interact with computers through a graphical user interface
(also GUI
). Its name is similarly clear: It's the interface
through which you use the computer, and its a graphical (as opposed to
textual or auditory) interface. Modern graphical user interfaces
stem from work at Xerox PARC, although they were introduced to the
broader consumer world through the Apple Macintosh. To most modern users,
the GUI is indistinguishable from the OS. (Programmers may still find
it useful to distinguish them.)
In Grinnell's computer science department, we use an operating system
known as Linux. Linux is distinguished by being an Open
operating system (which means that anyone who has the knowledge and
desire to make modifications to the program code of the operating system
is permitted to do so) and a Free operating system (which means
that it doesn't have to cost you anything to install it on your computer,
unlike the Macintosh OS, with a list price of about $150, or the Windows
OS, with a list price of about $400). Admittedly, the Linux community
uses Free
in two ways, in the way I used it above (as in Free
Beer
) and in the way I used Open
(as in Freedom
).
Why do we use Linux rather than Macintosh OS or Windows, particularly
since much of the rest of the institution uses Windows? One reason is
that we consider Linux to be technically superior: It is less likely to
crash, it is freer from viruses and other irritants, it has a much
longer history of separating what the average user can do from what the
administrator can do. More importantly, it is much more portable. You
can sit down at any MathLAN computer and have exactly the same set of
files naturally available. (Think about how many times you save a file
on one Windows box on campus, forget to move it to StorageServer, and
then cannot access it elsewhere on campus. That will never happen in
MathLAN.)
Many members of the department also have a philosophical preference for
the open source movement, of which Linux is an important part. We believe
that good software should be free, in both senses of the word.
Linux, unlike Macintosh OS X or Microsoft Windows, permits you to use
a variety of GUIs on top of the same underlying OS. We have chosen
to use a GUI called Gnome. Our experience suggests that
Gnome provides an appropriate balance of power, configurability, and
usability.
Gnome, like Windows, provides a task bar at the bottom of the screen.
You will click icons on the task bar to start applications. You may
use a popup menu on the task bar to log out
when you are done with
your work.
So, what does this all mean for you, other than that the computer
scientists at Grinnell worry about these things? It means that you will
have to use an unfamiliar GUI in this course (and in any future computer
science courses you take). Fortunately, Gnome is similar enough to other
operating systems (particularly to Microsoft Windows) that you should find
it fairly natural to use.
Like the Microsoft Windows boxes on campus, the MathLAN Linux workstations
require you to log in to use them. MathLAN uses an independent password
system, so you should remember that you have different passwords (unless
you take the time to make them the same). MathLAN passwords are stored
in such a way that no one, not even the system administrator, can extract
the original password, so it is safe to use the same password. (Of course,
someone trying to guess your password still has an opportunity to do so.)
In this course, you will be using a variety of programs. There are four
that I consider particularly important.
- DrScheme is the programming environment we use in the class.
You should be able to access DrScheme through the red-and-blue lambda
(λ) icon in the task bar.
- Iceweasel is the preferred Web browser in this course. Iceweasel
is a slightly-modified version of Mozialla Firefox, renamed because of
trademark issues (details at
http://en.wikipedia.org/wiki/IceWeasel).
You
should be able to access Iceweasel through the icon in the task bar that
shows a small white animal holding a green sphere..
- The terminal window supports textual interaction with the
operating system. At times, the terminal window provides the most
convenient way to interact. You should be able to access the terminal
window through the picture of the screen in the task bar.
- Icedove is the preferred Mail client in this course. Icedove
is a modified version of Mozialla Thunderbird. You
can also use Microsoft Outlook Web Access within the browser, if you
prefer. Student accounts are not configured to use Iceweasel by default,
so we will spend a bit of time reconfiguring your account. You typically
start Icedove from the terminal window.
;
