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Date: Mon, 24 Jun 1996 02:53:29 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199606231653.CAA13722@godzilla.zeta.org.au>
To: mark@grondar.za, mark@linus.demon.co.uk, sos@FreeBSD.ORG
Subject: Re: Syscons CUT&PASTE functionality added...
Cc: current@FreeBSD.ORG
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>I forgot to mention that bit in my other mail - I had to use the cuaa?
>device (/dev/cuaa1 in your case) instead!  (The more I poke at serial
>devices, the less I understand them...  My X server uses the ttyd? device
>just fine.)

That's because the X server (almost) (*) understands them.  It opens the
port with O_NONBLOCK mode and sets CLOCAL etc.  moused opens the port
without O_NONBLOCK so it hangs opening /dev/ttyd1.  Then it doesn't set
CLOCAL etc. (it only sets the speed).  This works for the default settings
of /dev/cuaa1.

(*) The X server (XFree3.1x at least) assumes that writes to the mouse
complete fairly soon.  If they hang (perhaps due to flow control being
locked on so that ther server can't turn it off), then the whole server
hangs.  IIRC all signals are usually masked when it writes to the mouse,
and killing it with -9 of course results in the screen not getting
switched back to text mode.

Bruce