Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hplabs!hpfcdc!perry
From: perry@hpfcdc.HP.COM (Perry Scott)
Newsgroups: comp.sys.hp
Subject: Re: Re: More HP-UX 6.5 puzzlements (long)
Message-ID: <5570185@hpfcdc.HP.COM>
Date: 15 May 89 20:06:18 GMT
References: <3344@fmeed1.UUCP>
Organization: HP Ft. Collins, Co.
Lines: 78

>Unfortunately, this is the way I was already set up.  Something changed
>with Revision 6.5.  Does anyone know what?  Is anyone out there using
>DTR control with HP-UX 6.5?  If so, can you tell me your set-up (special
>file minor number, etc...)? This capability is important to me.

If minor number 0xSC0001 (simple mode callout) is used and HUPCL is on,
then DTR should go down when the device file is closed.  That is the
documented behavior.  Admittedly, the TERMIO man page is a bit obscure,
but it's in there.

The callout file will raise DTR and wait for CD from the other side to
go high.  You could wire DTR to CD if the other side doesn't raise CD.


Re: * FLAME ON *

>I don't have time to read the documentation cover to cover before I
>attempt to implement something. So, there are times I just 'try it and
>see if it works'.

This sounds like a basic problem in documentation for a complex system.
The system is so big that nobody can know everything about anything.

>If a change is made to HP-UX to
>make the *actual* match the *documented*, that's great, *BUT*.........
>
>*PUT* *IT* *IN* *THE* *UPDATE* *NOTES*

Is this reasonable ?  There are hundreds of defects repaired in each
release.  If HP documents all of them, customers would either not read
it because the list is too intimidating, or the signal-to-noise ratio
would be too low to be useful.  If you are really saying you want to see
the impacts of several hundred defect fixes to the system, along with a
writeup of all the new features, I'll accept that.

>Both of the above mentioned situations (DTR on hang-up, %jobno syntax
>for ksh) were operating in a fashion that I took advantage of (I won't
>dispute whether the behavior was *correct* or not).  When I upgraded
>OS's, I changed nothing else (except for a 350 -> 370 upgrade; don't
>tell me *that's* my problem).

If you are using undocumented features, then I'm afraid it _is_ your
problem.  If you find a feature that does not work as documented, then
that is something you should tell HP about via the normal support
channels.  If DTR doesn't go down when HUPCL is set, let your SE know.

>The behavior of these items changed, and the system no longer operated
>in the same fashion.  I don't have the time to re-search the
>documentation, or re-learn the material.  I *make* time to read update
>notes.  I saw *NOTHING* in the update notes.

Again, I think there is a basic problem in the structure of the information
presented.  There is too much unstructured information to allow a person
to quickly find what they need to know.

>And while I'm on the subject
>of tty drivers, here's one:  Is there any way (minor number, etc...)  to
>enable hardware handshaking? 

If you "or" 0x08 into the minor number, a form of hardware handshake will
be enabled.  It isn't documented well because it isn't true hardware
handshake, but works for most applications.  When this bit is set, then
CTS being lowered it has the same effect as receiving XOFF.  When CTS
is raised, it has the effect of XON.  Since XON/XOFF is under control of
the s300 driver, it may not stop the data immediately and a few more
characters will dribble out - I don't know if the Telebit can handle this.
(BTW, this is all s300-only.)  The 98628's HWHS isn't used because UN*X
likes to think it is in control of the pacing.

>Thanks for letting me bend your ear :-)

I'll consider it bent.  Don't take what I say as official HP support
policy.  I'm just trying to help you get your job done, engineer-to-
engineer.

Perry Scott
HP Ft. Collins
..{ihnp4,hplabs}!hpfcla!perry-s