Ask SIPBStudent Information Processing Board
What if you don’t have Internet? If you have a modem and phone, MIT has a free service with which you can connect to Athena to accomplish most common tasks such as e-mail.
Question: When would I ever want to dial into MIT with my modem?
Answer: MIT’s free modem dial-up service is useful if you have a modem and want to connect to Athena from somewhere without Internet. You may be in this situation if you are traveling (and brought a computer with modem with you), if the network has gone down in your building, if you have a computer without Internet capability, or if you live off-campus and do not have an ISP.
This service is not to be confused with MIT Tether (http://web.mit.edu/is/help/tether/), a for-pay modem dial-up which works like a commercial ISP.
Question: What are the drawbacks of this service?
Answer: First and foremost, it is not really an Internet connection, but only a connection to Athena. Therefore, you will not be able to use programs such as your Web browser (Netscape, IE, etc.), Eudora, or AIM over the connection. We will describe how to browse the Web and check e-mail below.
The service is also very slow, running at 14.4 Kbps. A typical commercial telephone ISP is 56 Kbps, or 4 times faster. Your dorm network connection is probably 10 Mbps, or 700 times faster.
Finally, MIT Information Systems has notified us that they plan to discontinue this service in the near future. So on one hand, use it now, while it still exists; on the other hand, if you feel this service is useful and would like to see it continued, you can express your support to email@example.com and/ or your favorite appropriate MIT administrator.
Question: What software do I use?
Answer: Under Windows, you can use the built-in program HyperTerminal (in Accessories Communications). Under Macintosh, you will have to download and install a modem-terminal program; Zterm is a popular choice. Linux users often use Kermit or Minicom. A Web search will find these programs. There is a little chicken-and-egg problem of getting these programs if you have no Internet in the first place. You may want to copy them onto ZIP disks or burn them onto CD.
Question: What parameters do I use?
Answer: Whatever software you choose to use, you will probably have to enter some modem connection settings. The settings to enter are “8” Data bits, “No” Parity, and “1” Stop bit. (These are usually the default settings for Windows HyperTerminal.) For port speed, you should set 14400, and duplex “Full Duplex.” The “terminal emulation” you want is VT100 or VT102. To have the Backspace key work normally for programs such as Emacs, you want set the Backspace key to send “Delete.”
Question: What is the phone number?
Answer: The phone number is 617-258-7096. If you are dialing in from campus, only 8-7096 is needed.
If you are using this service while traveling and want to use a calling card, you will need to insert commas into the phone number to wait for the voice prompts. The commas create pauses during dialing. For example, for the TSI calling cards sold from the kiosk on the first floor of W20, you would enter the very long phone number “18773331815,,,,xxxxxxxxxx,,, 16172587096”, where “xxxxxxxxxx” is the PIN number for your phone card. Windows HyperTerminal also has a alternate interface for using a calling card that lets you specify the phone numbers, PIN, and the length of pauses in between.
Do NOT use a calling card with a high connect fee. The service is a little flaky, and it often requires a few tries until the connection works.
Question: How do I log into my Athena account?
Answer: After you connect, you will get a “pasta” prompt, usually “LASAGNE.MIT.EDU>.” Remember it may take a few tries to connect. At the pasta prompt, type athena to connect to Athena, and log on with your username and password. You will receive a warning the the connection is unencrypted. You can ignore it; the network between lasagne.mit.edu and athena.dialup.mit.edu is a secure network on which it is difficult for intruders to eavesdrop and steal your password. At the “Terminal type” prompt, you can usually just press Enter.
Question: How can I check e-mail?
Answer: Pine is the recommended program to check e-mail over a dial-up connection. Just type pine to start it. However, if you already use the various MH programs (inc, from, comp, send, etc.) then you can continue to use them, too.
Question: How do I browse the Web?
Answer: First, type add infoagents at the athena% prompt. The programs lynx and w3m are both text-mode web browsers. Lynx is more popular, and handles cookies correctly, while w3m handles tables well. Of course, neither program displays images. To start either program, type its name followed by the URL you wish to browse, for example lynx web.mit.edu.
If you use Mozilla in the Athena clusters, you can access your bookmarks file with the following commands:
athena% find .mozilla -name bookmarks.html
athena% lynx .mozilla/default/random/bookmarks.html
The exact output of the “find” command will differ from user to user. Copy the output of the “find” command to the argument to lynx (or w3m).
Question: How can I receive zephyrgrams?
Answer: There are two common programs that can handle zephyrgrams. You can type zwgc -ttymode at the athena% prompt to receive zephyrgrams directly on the terminal. Or, the program owl (http://web.mit.edu/ktools/www/owl.html, in the ktools locker) also manages zephyr well. The help command in owl is “h”, which will get you started. You can read more about owl from our March 7 column, at http://www.mit.edu/~asksipb/.
Question: How can I run multiple programs at once?
Answer: Unlike an Athena cluster workstation, you cannot have multiple terminal windows open at once running multiple programs. There are two ways to get around this limitation.
Typing Control-z will suspend the current program you are running and give you an Athena prompt, where you can start a new program. Typing jobs will give you a list of all the suspended programs you have, with a number to the left of each one. You can resume any suspended program with fg %N, where N is the number from the jobs command.
The other method is to use the very powerful “screen” program in the gnu locker. Start your first program, say pine, with screen pine. To create a new “virtual terminal”, type “Control-a c”. This will give you a new athena prompt. To switch between virtual terminals, type “Control-a n”. If you need to type “Control-a” for any application (like Emacs), type “Control-a a” instead. For example, to start pine, lynx, and owl, one would do
athena% add gnu ktools infoagents
athena% screen pine
Then, “Control-a n” switches between the programs.
Question: How can I transfer files?
Answer: Beware that transferring files is extremely slow. For downloading files from Athena to your computer, you can use sz (in the sipb locker), or kermit (does not require adding a locker). Kermit is more reliable, but is slower. To download a file with sz, simply type sz filename and the file will automatically start downloading. You might have to tell your modem terminal program to begin receiving a file. For kermit, start it with kermit, then type send filename.
For uploading files from your computer to Athena, only Kermit works. Start it with athena% kermit, then type receive to put Kermit in Receive mode. Next tell your modem terminal program to start sending a file using the Kermit protocol. For example, in HyperTerminal, use the Transfer menu.
After a transfer is complete, type quit to exit kermit.
As a note, do not try to run kermit or sz from within a “screen” session mentioned in the previous question. You cannot do anything on Athena while a file is transferring.
Question: How do I exit a modem dial-up session?
Answer: Type athena% exit. You may have to type it several times if you were running “screen.” At the lasagne.mit.edu prompt, type exit as well. Your modem should then hang up.
Question: How can I find out more information about this modem dial-up service?
Answer: Visit the Web page http://web.mit.edu/olh/ Dialup/Dialup.html.
To ask us a question, send e-mail to firstname.lastname@example.org. We’ll try to answer you quickly, and we might address your question in our next column. Copies of each column and pointers to additional information will be posted on our Web site: http://www.mit.edu/~asksipb/.