Ocean Acoustics Computer FAQ

MASSACHUSETTS INSTITUTE OF TECHNOLOGY
DEPARTMENT OF OCEAN ENGINEERING

OCEAN ACOUSTICS GROUP

77 Massachusetts Avenue, Room 5-204, Cambridge, Massachusetts 02139 USA

Computer FAQ

Below is a list of Frequently Asked Questions about the computers used the Ocean Acoustics Group.

Where are the computers?

Student computers are located in 5-435 and 5-007.
Where are the printers?

There are four printers available to students.

Printer Location Color or B/W Two-sided Transparencies

lp1 5-204 Color Yes Yes

lp2 5-435 Color No Yes

lp4 5-435 B/W Yes No

lp8 5-007 B/W No No
How do I print double-sided?

Double-sided (duplex) printing is supported on printers lp1 and lp4. Use the command:

lpr -Plp1 -Zduplex file.ps

lpr -Plp4 -Zduplex file.ps
How do I print on transparencies?

Color printers lp1 and lp2 have an additional paper tray which is pre-loaded with transaparencies. To have your file print automatically on transparencies, use the following command:

For lp1: lpr -Zinupper -Plp1 file.ps

For lp2: lpr -Zinlower -Plp2 file.ps
How do I read and print Adobe Acrobat (PDF) files?

Use the acroread command: acroread file.pdf

Which computer is the fastest? Which is the slowest?

During May, 2000, the following benchmarks were recorded using RAM, a floating-point intensive FORTRAN acoustic propagation program. Lower execution time means the program ran faster.

Hostname	Processor	MHz	Time (HH:MM)
sonar.mit.edu	EV67	667	12:01
dynamics.mit.edu	K7	600	37:31
monopole.mit.edu	EV5	333	43:37
boreas.mit.edu	PIII	600	56:54
multipath.mit.edu	PIII	600	58:33
vibration.mit.edu	PII	400	63:03
acoustics.mit.edu	PII	400	63:12
dipole.mit.edu	PII	333	83:52
acoustic.mit.edu	P6	200	179:00

What are the command line options to optimize FORTRAN?

On sonar and monopole, use the following compilation line:

fort -O -arch host -tune host -fast -o file file.f
How do I change my password?

Use the "yppasswd" command.
How often are backups performed?

Backups are automatically performed 6 days a week, from Monday through Saturday. The Amanda backup package is used. All computers are backed up on a rotation of 29 tapes (approximately 1 month's worth). Although configured to back up all computers nightly, occaisionally a larger disk will fill a backup tape completely, meaning the most recent backup available may be 2 or 3 days old.
Where can I run MATLAB?

MATLAB is available on most of the computers. Two methods are available: running the MIT Project Athena licensed version, and the other is the running the locally licensed version. While the Athena version has more toolboxes than the local version, the Athena version requires you to renew your Kerberos tickets at regular intervals. If you are running a long MATLAB batch job (which is discouraged), using the local version would be recommended.

Hostname Athena or Local

acoustics.mit.edu Athena

acoustic.mit.edu Athena

vibration.mit.edu Athena

dipole.mit.edu Athena

multipath.mit.edu Local

dynamics.mit.edu Athena

sonar.mit.edu Local
Why can't I use telnet or ftp?

Short Answer: Use ssh instead.

Long Answer: Telnet and FTP allow transmission of usernames and passwords "in the clear" across a computer network. In the Fall of 1997 an intruder installed a packet sniffer on the Building 5 subnet. He was able to collect passwords of students in the group, gaining access to several machines. He then used these machines to attack other computers around the world. Recovery involved re-loading the operating system of all computers in the group, a process which took nearly 1 week. To avoid repetition of such an incident in the future, Profs. Schmidt and Baggeroer dictated that telnet and ftp would not be used on any group machine in the future.
I use Microsoft Windows at home. How do I get SSH for Windows?

MIT has a site-license for SecureCRT a Windows version of SSH. You can download a copy from the MIT distribution site. The license information (which you will need to enter on the first run) is located here. Remember that the SSH servers on sonar, etc. run SSH version 2.
How do I transfer files using SecureCRT?

SecureCRT includes support for the Zmodem file transfer protocol. To send a file from your PC to the acoustics computers, type:

rz -e

on the UNIX command line. A dialog box will appear allowing you to select which file to send. To send a file from the acoustics computers to your PC, type:

sz -e filename

on the UNIX command line. The file will be transferred and stored on the Windows hard drive, under C:\Program Files\SecureCRT\downloads.
SecureCRT is good, but it allows only a text-based terminal session. How can I get graphics from the UNIX system to display on my Windows PC?

Download and install the VNC software package. This software will allow you to display X windows on your PC. Establish a SecureCRT connection to acoustics.mit.edu, then run the VNC server, using the command:

vncserver

The server will ask you for a password. This password should not be your login password, but one for VNC only. The server will give you a display number, of the form: acoustics.mit.edu:N where N is a number. Remember this. Then, run the vncviewer program on your PC. It will ask for a display (enter acoustics.mit.edu:N, where N is the number from vncserver). It will also ask for the password you typed while running vncserver. Enter it, and then an X-windows session will appear on your Windows desktop. You can run MATLAB and any other graphics program from there.
How do I duplicate a CD?

Two CD-ROM burners are available for use by students in 5-435. One is attached to acoustics.mit.edu, the other, vibration.mit.edu. The CD-ROM burner on acoustics is twice as fast as the one on vibration. To duplicate a CD, first insert the source CD into your computer's CD-ROM drive, and type:

dd if=/dev/cdrom of=/vibration0/tmp/mycd.iso ibs=2048

Then, insert a blank CD into the CD-ROM burner you have selected (either acoustics or vibration).
Type the command:

cdrecord -v /vibration0/tmp/mycd.iso

When complete, eject both source and copy CD, and remove the temporary ISO image:

rm /vibration0/tmp/mycd.iso
How do I back up my files to a CD?

A CD-ROM can hold only about 650 MB of information. Group all your files into a directory tree. Make an ISO image of the directory tree with the following commands:

cd directory-name
mkisofs -a -f -v -r -T -J -o /vibration0/tmp/mycd.iso .

Note the "." at the end of the mkisofs command line. This will copy all files in and under the directory directory-name into an ISO image. Insert a blank CD-ROM into either acoustics or vibration, and log into either acoustics or vibration using the ssh command. Once logged in, copy the ISO image to the blank CD-ROM using the command:

cdrecord -v /vibration0/tmp/mycd.iso

When complete, eject the new CD, and remove the temporary ISO image:

rm /vibration0/tmp/mycd.iso
I need to draw a diagram. What is a good drawing program under X-windows?

xfig is a MacDraw-like program which allows you to generate high quality vector based figures. You can also incorporate (and annotate) encapsulated PostScript, JPEG, and GIF files. The result can be re-exported in EPS (or JPEG, GIF, etc.) format for inclusion into LaTeX.
I really need to view a Microsoft Word/Excel/PowerPoint document which someone sent me via e-mail. How do I do this?

VMware allows one to run a virtual Windows 98 session on a linux box. VMware is installed on acoustics.mit.edu, vibration.mit.edu, dipole.mit.edu, multipath.mit.edu, boreas.mit.edu and reverb.mit.edu. Due to licensing restrictions, only one person can use VMware at a time. Please respect this and use latex for scientific documentation, gnumeric for spreadsheets, and slitex for presentations.
Someone sent me a document as an attachment in an e-mail message, but the mail program did not recognize it as a separate file. How do I rescue the attachment?

1. Save the e-mail message as a file.
2. Edit the e-mail message to strip out all uneccessary text. For example, a file which looks like this:

--=====================_960558251==_ Content-Type: application/msword; name="ECUA PROV PROGRAMME.doc"; x-mac-type="42494E41"; x-mac-creator="4D535744" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="ECUA PROV PROGRAMME.doc" 0M8R4KGxGuEAAAAAAAAAAAAAAAAAAAAAPgADAP7/CQAGAAAAAAAAAAAAAAAOAAAA1gYAAAAAAAAA EAAA2AYAAAEAAAD+////AAAAAMgGAADJBgAAygYAAMsGAADMBgAAzQYAAM4GAADPBgAA0AYAANEG (lots of lines) AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAA --=====================_960558251==_--
...would be edited down to:

0M8R4KGxGuEAAAAAAAAAAAAAAAAAAAAAPgADAP7/CQAGAAAAAAAAAAAAAAAOAAAA1gYAAAAAAAAA EAAA2AYAAAEAAAD+////AAAAAMgGAADJBgAAygYAAMsGAADMBgAAzQYAAM4GAADPBgAA0AYAANEG (lots of lines) AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAA
3. Run mimencode to decode it:

mimencode -u -o output_file input_file
I would like to use the Compaq Fortran compiler "fort" on Alpha Linux, but gdb under emacs does not work well with it. What should I do?

Please use "ladebug" instead. The Fortran code has to be compiled with "-g -ladebug" options. For example:
```
fort -g -ladebug foo.out foo.f
```
If you would like to run ladebug under emacs, please add the following code in your ~/.emacs file:
```
;; ladebug
(load-file "/usr/lib/emacs/lisp/ladebug.el")
```
You can run it with:
```
M-x ladebug RET
```
under emacs.
For more information about fort and ladebug, please consult:
- Compaq Fortran User Manual for Tru64 UNIX and Linux Alpha Systems
- Ladebug Debugger Manual
I use xfig and export an EPS file. When I use "lpr -Plp4 foo.eps" to print it, it does not print at all.

There may be one line like this in the EPS file:
/showpage {} def
Use any text editor such as emacs or vi to delete it or comment out that line like this:
%%/showpage {} def
and it will work.

I want to use our local JASA database. When I click the file I want to browse, it shows "AT&T FORM" but not the page I want.

1. Please check that you are using an x86 based Linux machine i.e. you are not using sonar.mit.edu or monopole.mit.edu.
2. Your DjVu plugin may not be properly installed. Click this link to install it.

I want to use VMWare but the computer tells me that someone else is using it

We only have one license for VMWare so if someone else is using it you will have to wait until they are done.

If no one else is using it and you still get the error message then there is probably an old lock file that needs to be deleted. Go to the directory /multipath0/vmware/win98 and delete the file win98.WRITELOCK.

Last updated: 010202
Comments/Questions: webmaster@arctic.mit.edu

Printer	Location	Color or B/W	Two-sided	Transparencies
lp1	5-204	Color	Yes	Yes
lp2	5-435	Color	No	Yes
lp4	5-435	B/W	Yes	No
lp8	5-007	B/W	No	No

Hostname	Athena or Local
acoustics.mit.edu	Athena
acoustic.mit.edu	Athena
vibration.mit.edu	Athena
dipole.mit.edu	Athena
multipath.mit.edu	Local
dynamics.mit.edu	Athena
sonar.mit.edu	Local