[4376] in Athena Bugs
Re: PVAX/PMAX serial driver
daemon@ATHENA.MIT.EDU (epeisach@ATHENA.MIT.EDU)
Fri Mar 2 19:05:44 1990
From: epeisach@ATHENA.MIT.EDU
Date: Fri, 2 Mar 90 19:05:10 -0500
To: bugs@ATHENA.MIT.EDU
If I remember correctly, someone stated that 1) The DS3100 and VS 3100
ports were different. And 2) That the DS3100 port did not have the
proper port. The following may imply that the hardware is the same, but
I don't know.
The following notes from comp.sys.dec might be of interest:
Regarding the vs3100
Problem here is that the VS3100 doesn't support full modem
control on either port.
tty03 has DTR set high all the time which your modem might want
to see. BTW, neither port looks at DSR.
If u can set DTR high on the modem, do so. That ensures that it
will always answer the phone.
Real trick here is not to tell your machine that it's a modem
port. That's because modem signals aren't much supported. Pretend
it's a direct connect terminal (but keep using the same cable) and
it should work ok.
The problem with keeping DTR high all the time is that you're not
going to be able to control hangup and session ends. But you're
not going to be able to control DTR in any case because you can't
tell your machine you have a modem. Therefore, users will have to
be sure to hang up the phone after they finish a session.
Pretty garbled answer but u probably get the idea.
---------------------------------------------
Regarding the DS3100
What modem port?
The built-in tty ports on the DS3100 are virtually useless for anything
but hardwired lines, as they implement only receive and transmit signals.
(They also, it seems, cheat on the output levels.) Although you could
connect these ports to a dial-out modem, you would never be able to tell
if it lost its connection (no DTR).
