DTR Problems (and some RS-232 flamage)

[roy at phri.UUCP]

In article <1995 at emory.UUCP> km at emory.UUCP writes:
> We have been having the following problem on 4.3BSD (acutally the
> Mt Xinu release) [...] Getty does not always raise DTR on its port.

	Perhaps this is too trivial to even mention, but I'll mention it
anyway.  On 4.2, the dmf lines are called h0->hf, i0-if, etc.  Under 4.3
they are called A0->A7, B0->B7, C0->C7, etc.  Also the /etc/ttys file has
been completely restructured.  The conversion is straight-forward, but
tedious to implement (i.e. involves a fair amount of manual editing).
Between the renaming of the tty lines and the merging of several files into
one (both good things, BTW) we managed to botch a few things in our new
/etc/ttys file at first.  This caused random strange things to happen, some
of which match your symptoms.  Could this possibly be the cause of some of
your problems?

	For some more conventional suggestions, check the dmf flags in your
config file to make sure modem control is {en,dis}abled on the right lines
(another thing we botched on the first go-round).  Make sure acucntrl isn't
playing games on you; try making all your modems unidirectional until you
figure out what's wrong, simply to reduce the number of variables.  If
you're using a mix of Emulex CS-21's and DEC DMF-32's, remember that only
the first two lines on the DEC board have modem control, and that while all
the Emulex lines do, it doesn't quite match that on the DEC board.

	BTW, can somebody explain to me why the DEC DMF-32, with all the
zillions of random modem signals it lets you get at, still doesn't let you
read the HS line?  It sure would be a nice way to autobaud a 1200/2400
modem (as in that's what the signal is designed for).  While I'm at it, fie
on US Robotics for not making their Courier toggle HS when it makes a
connection at 1200.  For all the braindamage my old CTS-2424 had, at least
it did this properly.  RS-232 is such a wonderful standard -- with 25
signals, there are (at least) 2^25 ways to implement it, and I'm sure if
you looked long enough you would find at least one manufacturer who had
implemented each one.
-- 
Roy Smith, {allegra,cmcl2,philabs}!phri!roy
System Administrator, Public Health Research Institute
455 First Avenue, New York, NY 10016

"you can't spell deoxyribonucleic without unix!"