Java Information

The department's introductory course (CS11) teaches Java as part of a more general introduction to Computer Science. If you have no experience with programming, CS11 is a good place to start.

If you already know a programming language fairly well and want to learn some Java on your own, we recommend Patrick Henry Winston's book On To Java. It concentrates on what you need to know to get started writing Java programs quickly. It is also inexpensive.

Other Java Information

The Amherst CS Computing Network: A Brief Introduction

Our equipment

We have a variety of servers and X terminals. Our main public server, Sirius, is a 3GHz dual-processor Pentium Xeon running Redhat Linux. The student lab is room 007 of the Seeley Mudd Building.

Who can use the network

Access to the department network is restricted to faculty, majors in computer science, and students in certain upper-level computer science classes. Users can usually be issued keys to the lab.

Accessing Sirius

The official name of Sirius is "". For security reasons, telnet and ftp are not available.

SSH is a secure replacement for telnet. Many different SSH clients are available. The IT department has information about installing and using an SSH client. Sirius itself has a program "ssh" that you can use to reach other machines. A similar command is available on Mac OS X.

SFTP is a secure replacement for ftp. The IT department has information on how you can install and use this software.


Graphical (X windows) access to Sirius is available by using a VNC Viewer. When you make a connection, refer to

to get a window that fits on most PCs or

to get one that's larger.

Shell and start-up files

The default shell for new users is tcsh. Let one of the faculty know if you'd like your shell changed.

New users are given .login and .cshrc files. Edit the .cshrc file to create aliases or to make other changes to your environment.


The best browser on Sirius seems to be Mozilla. It's a variant of Netscape 7.0 and can be accessed by clicking the second icon from the right on the control panel or with the command "mozilla". Mozilla has a fairly good e-mail facility.

Let us know if there are other browsers we should mention here. Internet Explorer does not seem to be available for Linux.


There are currently four printers configured from Sirius:

  • cs4 --- The fourth floor printer

  • cs3 --- The third floor printer

  • uniprint --- The printers in the computer center

  • webster --- The printer in the Webster computer lab

Students should only use the "uniprint" and "webster" printers. The default printer for students is "uniprint". Students are charged for printing according to IT department policies.

The default printer for faculty is "cs4".

To change your default printer, put the following line in your .cshrc file:

setenv LPDEST uniprint

You should of course specify whatever printer you want to use. The new printer will become the default in any new windows you create. To change printers in your current terminal window, simply type the command into the window.

The command

lp Whatever

will print a text file on your default printer in a typewriter font. The lp command can also print Postscript files. Use the command

enscript Whatever

to do printing of text files with better formatting, or

enscript -G2rE

to get a two-column rotated listing of a Java program.


E-mail for students is forwarded to the College's main mail servers.

Maintaining Web Sites on Sirius

User websites are maintained in the directory /mnt/www/users. Each user has an individual subdirectory. Be sure that all files you put in your web area have the right privileges; all files should be readable by everyone and all directories should be readable and executable. You can look at your website by pointing your browser at

For security reasons, ftp is not available on sirius, which makes it a little harder to use some web design software, such as Dreamweaver. The IT Department has information on how to use tunnelling with ssh to permit secure file transfer. You should use ssh to connect to sirius, and you should create a tunnel from port 2021 on "localhost" to port 21 on "". This should be a local tunnel, one originating at the local end of the ssh connection.

Changing passwords

Use the command "passwd".

On-line help

There is an extensive on-line manual of all commands and system calls. For help on the command "ls", just type

man ls

To print up a copy of the manual entry on the laserprinter, type

man -t ls

Documentation for Redhat Linux

Documentation for Redhat Linux is available at the Redhat website.


Let one of the computer science faculty know. We would welcome contributions to this documentation.