[comp.unix.xenix] An interesting discovery....

root@mjbtn.MFEE.TN.US (Mark J. Bailey) (10/23/88)

I apologize for the wide spread of groups I posted to, but I felt that the
people that MIGHT benefit from this would be found in varying areas.

A while back, I was having considerable difficulty with my Prometheus 2400G
stand-alone (Hayes clone) modem getting stuck with getty answering at 1200
while it should be answering at 2400.  It seems that the modem (and others
like it) had a problem with answering at the speed at which they were last
addressed, in this case getty.  I had several people give input to my cause
which was finally solved when I replaced my init with Sandy Zelkovitz's 
Xenix init replacement, and modemctl (getty replacement) posted to 
comp.sources.unix back in the summer.

One source suggested to me that I place an 'A' or two in my gettydefs
string and that when the modem connected, and getty sent the login prompt,
the 'A's in the string would "sync" the modem to the getty speed, supposedly
2400.  Well, I tried it, and it really didn't solve my problem, so I went
on to the next one.

Then about two weeks ago, the TB+ I ordered came in and I proceeded to
install it on my system.  The biggest problem I had was when I connected
to the TB+ from a remote site, I had to hit CR's, BREAKs, NLs, etc., just
to get the login prompt.  I then recalled what the above source had told
me about the 'A's, so while try to pound the BREAKs and CRs to get a login,
I started hitting 'A's and the minute I hit the second one, up comes the
login prompt.  Now, I know with S51=254, your system-to-TB+ speed starts
at 19,200, but will autobaud if you hit 'A's, but I never thought it would
work from the remote side.  Well, it did.  I then proceeded (eagarly at 
this point) to put 'AA' in my gettydefs login string.  When I dialed
the system back up, the login prompt came up IMMEDIATELY!  Here is my
string:

AA-Telebit (Port tty2A)
mjbtn!login:

(I had to make it a little official looking :-)

I did some more tests to see if it was a fluke, but the tests proved
conclusive that it at least worked on my Xenix system.  It seems that 
as getty sends the AA string, the TB+ is able to recognize what speed
the modem is connected at and sync to that speed, instead of the 19,200
baud coming from the system.  I commend Telebit on this feature!  

Some of you may already know this as OLD news.  If so, I apologize to
you and to those who don't give a flip.  It has really made life easier 
here and I hope that it might be of service to some others.  Sorry for
the long posting!

Good Luck!

Mark.

-- 
Mark J. Bailey                                    "Y'all com bak naw, ya hear!"
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