Mac OS X (all versions) include ssh software. To connect to Helix with a text-based connection (no graphics), use the Terminal program on the Mac.

In the "Utilities" folder, find the "Terminal" icon and double-click to start. In the terminal window that opens, at the prompt, type

The first time you run ssh, you will see this message:

The authenticity of host 'helix.nih.gov (128.231.2.3)' can't be
established.
RSA key fingerprint is
e9:87:ba:5b:4b:fd:ca:82:04:79:c1:60:b3:99:95:75.
Are you sure you want to continue connecting (yes/no)?

Type yes to accept the connection. After the first time, you will no longer see this message.

You should now see the 'Notice to Users' from helix, after which you will be prompted for your Helix password. After you enter your password successfully, you will get the Helix prompt and will be logged on to Helix.

[aaa:~] localuser% ssh username@helix.nih.gov
                           Notice to Users

 This U.S. Government computer system is provided for authorized use
 only.  Any and all uses of this system and all files on this system
 may be monitored, copied or disclosed by authorized personnel.  The
 data on the system may be searched at the request of law enforcement
 or other persons, as appropriate, and may be disclosed and used for
 disciplinary or civil action or criminal prosecution.  Use of this
 computer system constitutes consent to these policies, which may take
 precedence over privacy rights.

username@helix.nih.gov's password: 
Last login: Tue Jan 24 11:04:42 2006 from aaa.nci.nih.gov
You have old mail.
Erase on Backspace key or Delete key (b or d)? b
Tue Jan 24 11:14:27 EST 2006
helix%

At this point you are logged on to Helix, and can run all Helix programs.

Making an Xwindows Connection

X-windows software allows users the ability to run graphics applications remotely & display their graphics locally. If you have Mac OS X v 10.3 or up, you can download X11 for Mac OS X from: http://www.apple.com/support/downloads/x11formacosx.html. Once you have the software downloaded and installed on your machine, click on the X11 icon in the Applications or Utilities menu to start up X11. You should see an xterm window appear. This window will look much like the Terminal window shown above.

In the xterm window, type

export DISPLAY=localhost:0.0 ssh -Y username@helix.nih.gov

Sample session:

[aaa:~] localuser% export DISPLAY=localhost:0.0
[aaa:~] localuser% ssh -Y username@helix.nih.gov
                           Notice to Users

 This U.S. Government computer system is provided for authorized use
 only.  Any and all uses of this system and all files on this system
 may be monitored, copied or disclosed by authorized personnel.  The
 data on the system may be searched at the request of law enforcement
 or other persons, as appropriate, and may be disclosed and used for
 disciplinary or civil action or criminal prosecution.  Use of this
 computer system constitutes consent to these policies, which may take
 precedence over privacy rights.

username@helix.nih.gov's password: 
Last login: Tue Jan 24 11:14:11 2006 from jasper.cit.nih.gov
You have old mail.
Erase on Backspace key or Delete key (b or d)? b
Tue Jan 24 11:25:27 EST 2006
helix%

At this point you are logged on to Helix and can run Xwindows programs. To test, type 'xclock' at the Helix prompt. You should see a clock window appear on your desktop, as below: