You can use "zwrite" to communicate with other people on Athena, but you can't
use it outside of Athena.  And, if your friend is on dialup, or for some other
reason is not using zephyr, you can use the "talk" command to communicate
anyway.

I.   The command syntax, from your unix (athena%) prompt, is:

	talk username@hostname

     where "username" is your friend's username, and "hostname" is the Internet
     address of the machine s/he's on.  For example:

	talk myfriend@w20-575-22
	talk myfriend@uxa.cso.uiuc.edu

II.  What happens next?

     In the same xterm where you typed the "talk" command:
	- your window will clear, and then will be divided in half
	- the message "No connection yet" will appear briefly
	- the message "Waiting for your party to respond" will appear
	- if your friend doesn't respond, eventually you'll start
	  getting the message "Ringing your party again"
	- once your friend responds, you'll get the message "Connection
	  established"
	- Now you can start typing!  Your friend will see what you type
	  as you type it, and you'll see what your friend types, too.
	- If *either* party exits "talk" (with a control-c) then you
	  will go right back to your unix (athena%) prompt.

III. What if it didn't work right?

     The "talk" command depends upon a number of things to work successfully.
	1. both computers must use the same underlying protocol (ie, speak
	   the same language) for "talk"
	2. both computers must know about each other's existence and
	   there must be an internet network connection between the
	   two computers
	3. both people trying to talk must be logged in

1. If you get the message "checking for invitation on caller's machine",
   and this message doesn't change to something else after about 60
   seconds, then one of two things may be wrong.
	- the connection between the two machines may not be working
	- the other computer may use a different talk protocol

   If you know from previous experience that you usually *can* talk to the
   other computer, then the connection is probably not working.  Try again
   later. 

   If you don't know that, try the alternate command "otalk", which uses
   a different underlying protocol.  To use it, type:

        otalk username@hostname

   From *your* point of view, both "talk" and "otalk" work the same.
   However, because the underlying protocols are different, "otalk"
   may connect you successfully to computers with which "talk" won't
   work.  Even this command may not work, though, if the other computer
   is adequately out of date. 

   NOTE:  otalk does not exist on all types of workstations, such
          as the RS/6000 or SGI, for example.

   Another choice is to use the "ytalk" program available from the sipb 
   locker.  Type:

	add sipb
	man ytalk

   for more information about this program.  It works like "talk", but is
   more robust, and might be able to work with more different types of 
   workstations than "talk".  Please refer to the manual page for more
   details.
	
2. If you get the error message "can't figure out network address", then
   the other computer is not accessable from Athena.  You'll have to resort
   to more ancient means of communication, such as the telephone.

3. If your screen flashes very quickly, it means that either the other
   person is not logged in, or that the other person doesn't have an
   account on the computer you specified.  (The "flash" is actually "talk"
   starting up, not-finding the other user, sending you an error message
   which it doesn't give you time to read, and exiting.)

If you come across another error, it might fit into one of the above
categories, or it might be an unrelated problem.  In either event, feel free
to ask in olc, and we'll try to help, or at least to explain what the problem
is.

last updated: 10/23/95