Dave-Yost@RAND-UNIX@sri-unix (05/30/82)
Sender: day at RAND-UNIX Date: Monday, 3 May 1982 15:30-PDT Has anyone worked out a way that you can use a line for uucp dialout, and still have it available for dialin when uucp is not dialing out? That is, automatically? I know you can screw around by hand and edit /etc/ttys, kill -2 1, etc. --dave
mike@sri-unix (06/01/82)
I have been experimenting with a method of turning a dialin line around for dialout. We are currently limited to 4 dialin lines on our vax. With the recent upgrade for Vadic modems (to become dialers) , two of those lines are capable of dialing out. I have chosen the following for my strategy: All incoming calls start at one end with dialing out starting at the other end. I use the execute bit of the tty special file to indicate if getty is hanging on the line or not. Init sets the tty file mode to 623. Login changes the mode to 622. By looking at the execute bit, I can determine whether or not I can disable the getty on the line and dial out. I am currently implementing this code in uucp. I utilize a program called enable(8) for enabling or disabling getty on a line. Enable was submitted to Usenix (at Santa Monica) for distribution. I have successfully implemented this code in our equivalent of cu(1). I am also planning to implement this protocol for tip(1). The key to my protocol is simply using the execute bit as my semaphore. It has no other use for a tty special file. Once completed I will probably distribute the changes via usenix. This protocol has proven reliable in allowing uucp and our cu program to share a leased line between 2 remote systems. My current task is more concerned with talking to the Vadic intelligently rather than turning around the line. As many comments have indicated - the Vadic was designed for interactive use by a human with no nice and simple protocal for talking with a computer. Michael Wendel General Instrument Corp. Corporate Research and Development ucbvax!menlo70!sytek!gi