Computone + modem = ?

[Bill Vermillion]

In article <337 at crash.cts.com> bblue at crash.cts.com (Bill Blue) writes:
(many lines describing several different Computone probs deleted - wjv )
 
>	2. uucp simply couldn't talk if the device used was
>a major computone port (m0 as opposed to i0).  This was really
>difficult to track down, and once I did it took forever getting
>them to believe it.  The problem was that they weren't initializing
>the ioctl structure to a known state (all zero's, basically).  
>So when it was passed to an application which &= and |= to set
>states, it would fail.  If all parms were set absolute, it would
>work.  Fixed.  Grudgingly.

Re: not initializing the ioctl to a know state.

I had an experience that I shall pass on that may help others.  The system was
an AT but it was using IBM's Xenix 2.0 (I couldn't change that - they were
commited to that OS).

Working on some output to rf modems I discovered that in that version of Xenix
you could not use the &= or |=.  This was a system bug.  You had to set
absolute parameters, and restore the old one upon exit.  On the other hand
their creat call was "anded" with the system values, and would not use the
explicit values unless you cleared umask ahead of time.  Gawd! What a broken
system that was.



-- 
Bill Vermillion - UUCP: {uiucuxc,hoptoad,petsd}!peora!tarpit!bilver!bill
                      : bill at bilver.UUCP