zemon@felix.UUCP (10/28/87)
Reply-Path: I am interested in finding out two pieces of info concerning modems and Ultrix - currently 1.2, some day 2.?. 1. How can we set up a Microvax II using the Dec serial board (I dont know its name right now - sorry) to handle 9600 baud; I have been told that it will lose characters at this or higher speeds? 2. Is there ANYWAY that we can set up the system so that a naieve user, coming in to a modem capable of autobauding, can have the modem and unix automagically determine the caller's speed and adjust itself to this speed? Currently, we have things set up where the user has to send a break to change baud speeds. I would like to find a way for the software to determine the baud rate by looking at what the user is coming in as - perhaps with a return if necessary. Thanks for any info. Locations of appropriate code, books, magazine article references, etc. all all apreciated. Locations for code need to be accessible via mail or uucp though. Thanks again.
zemon@felix.UUCP (10/29/87)
Reply-Path: In article <11008@felix.UUCP>, lwv@n8emr.UUCP (Larry W. Virden) writes: > 2. Is there ANYWAY that we can set up the system so that a naieve > user, coming in to a modem capable of autobauding, can have the modem > [comment about sending breaks for speeding] If your system is anything like ours, if you make shure that your gettydefs definitions cycle from higher to lower speeds [i.e. 2400->1200->300->2400] the pressing of return repeatedly will sellect the speed by cycling until you reach the valid speed. The system should continue to advance every time you get an "invalid character or break" so it should work. The big problem is that some machines will not necessarily reccognize a CR at 2400 when gettys are expecting 300. The the shorter character frame will not trigger the sense if you go 300->1200->2400->300. [i.e. if you send a CR at 2400 it will not necessarily invalidate a 300 baud frame because of the timing of the start and stop bits (this is especially noticable when you are at 19.2 while gettys is expecting 1200)] Rob.
zemon@felix.UUCP (10/30/87)
I use Multitech 224 modems on my system. The nice feature that it has is built in speed translation. The modem is hooked up at, in our case, 2400 baud only. If a user comes in at 1200 buad, the modem switches to 1200 baud but still communicates with the VAX at 2400 baud. The only problem with this is that the VAX thinks that you are running at 2400 baud regardless of what speed you are running. Bradley Wong Viratek, Inc. UUCP: ucbvax!ucivax!mickey!bwong
zemon@felix.UUCP (10/31/87)
In article <11008@felix.UUCP> lwv@n8emr.UUCP (Larry W. Virden) writes: > >2. Is there ANYWAY that we can set up the system so that a naieve >user, coming in to a modem capable of autobauding, can have the modem >and unix automagically determine the caller's speed and adjust itself >to this speed? One can inform getty (via gettytab) that a line will be able to be speed sensed with a CR. You will have to add an entry to /etc/gettytab and make appropriate changes to /etc/ttys. Here is our gettytab entry: A|Auto-Baud:\ :ab:sp#2400:f0#040: This works for speeds from 110-9600baud. We currently use it in association with 64 ports (DHU-11) connected to a Gandalf PACX 1000. With the Gandalf, if passthrough is defined, the user will simply see the login: prompt at any speed in the range indicated above; otherwise CR must be pressed at least once.