two-way communication through the same port under SunOs 4.0

[Jim Budler]

In article <175 at cubsun.BIO.COLUMBIA.EDU>:
> According to my SunOs 4.0 manuals, as of this release you're supposed to
> be able to run a getty on ttya to enable logins, and simultaneously hook
> an outgoing modem onto the same hardware port, calling it /dev/cua0.

crw-rw----  1 uucp     devices   12, 128 Nov 26 07:43 /dev/cua0
crw--w----  1 jim      tty       12,   0 Nov 26 10:24 /dev/ttyd0

It is the same port, but it uses the minor number + 128.

> Whichever application (login or, eg, tip) grabs the port first is supposed
> to lock it to other applications.  I've tried this...the getty on ttya
> ...renders /dev/cua0 busy for outgoing calls...

Working fine for me.

> This is on a 386i, but a colleague trying the identical things on a 3-160
> running 4.0 exhibits the identical symptoms.

My machine is also a sun 386i.

> Has anyone gotten it to work, or is it a known bug, or what?

Two possibilities:

1) That is the way it would act if whatever is attached to the port
   asserts carrier detect all the time.

2) I configured my 386i before I got the documentation, so I set zs0 flags
   0 in the config file, like you did under sun OS 3.x. The documentation,
   when it arrived implies this is no longer necessary. I haven't tried it
   without.

jim
-- 
Jim Budler   address = uucp: ...!{decwrl,uunet}!eda!jim OR domain: jim at eda.com