Serial line problems under SunOS4.0
Ralph P. Sobek
ralph at laas.laas.fr
Sat Jan 14 05:24:07 AEST 1989
In our lab we normally have all our consoles set at 8-bits, no parity. We
just tried to attach two consoles to devices ttya and ttyb on our
Sun-3/60M running under SunOS4.0. I am unable to set ttya to remain
8-bits w/0 parity, and our system engineer is not familiar with
asynchronous lines. Our system engineer said that we have never had such
problems under 3.x, so maybe this is a problem with 4.0. As Bob Cuningham
in article <8812051941.AA14574 at kahala.hig.Hawaii.Edu>,
bob at kahala.hig.hawaii.edu (Bob Cunningham) writes:
| Here is a quick overview of most of the fixes for Sun3s:
|
| *LOTS* of serial driver fixes, including some ALM-II fixes
[The emphasis is mine.]
Our problem is that ttya wants to be 7-bits with even parity. Initially,
everything on the screen came as 7-bits, even. Changing /etc/gettytab
entry for std.9600 to include the option `p8' allowed the login prompt to
be issued correctly. Adding the same option to the default entry allowed
the `Password:' prompt and the banner to be issued correctly. After that,
the machine switchs to 7-bits, even parity.
Only when the line is physically deconnected over a period of time will
the session be carried out 8-bits, no parity according to stty. After
logout, it will revert to the above behavior of switching to 7-bits, even
parity after the start of the next login. Sorry for not being more
specific but I do not understand the system's behavior more precisely, but
recently even a physical disconnection was unsuccessful to keep a session
at 8-bits, w/o parity.
As an aside, ttyb declares itself to be 7-bits, even parity but does not
care if a console configured at 8-bits no-parity is connected.
A related question is how does one activate RTS/CTS flow control?
Thanks in advance,
Ralph P. Sobek Disclaimer: The above ruminations are my own.
ralph at laas.laas.fr Addresses are ordered by importance.
ralph at laas.uucp, or ...!uunet!mcvax!laas!ralph If all else fails, try:
SOBEK at FRMOP11.BITNET sobek at eclair.Berkeley.EDU
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