fgk@well.sf.ca.us (Frank G Kienast) (05/31/90)
At work, I am trying to connect a Hayes-compatible modem to an AT&T 3B15 computer. I have found that, in order to make outgoing calls using cu, it is necessary to wire the cable so that DCD (carrier detect, pin 8) is always high (otherwise I get the message "Can't access device" whenever I try to call out). But having DCD high all the time creates problems when I am ready to disconnect after a call. After the other end hangs up, I get the "NO CARRIER" message from the modem, but my terminal is still connected. The only two ways I have found to break the connection so another terminal can call out or someone can call in are: 1) Turn off the modem. This results is an immediate "Lost Carrier" messages and returns me to the Unix prompt. When the modem is turned back on, it is ready for the next call. 2) Enter "~.." (tilde dot dot). This returns me to the prompt, but it is necessary to log in as root and kill the uugetty on the modem line to free it for further incoming or outgoing calls. Is there any way to wire my modem differently or somehow set some parameter differently so my modem will disconnect properly? Please E-mail your responses. I will post a summary along with the results. In real life: Frank Kienast Well: well!fgk@ucbvax.Berkeley.EDU CIS: 73327,3073 V-mail: 804-980-3733
fgk@well.sf.ca.us (Frank G Kienast) (06/11/90)
I recently posted a question about a problem with using a modem on a 3B15. The problem is that DCD must be high to make outgoing calls, but holding it high all the time prevents proper disconnect after the call, requiring either turning the modem off or killing the uugetty. Thanks Pete Holsberg <apple!Princeton.EDU!pjh%mccc> for pointing out that the problem is a bug in SV, which is fixed in release 3.2. Since 3.2 is not available for our 3B15, I will probably move the modem to one of our other computers (which has 3.2) and access the 15 through our network. In real life: Frank Kienast Well: well!fgk@ucbvax.Berkeley.EDU CIS: 73327,3073 V-mail: 804-980-3733