Ken Hornstein writes:
> I've never been able to use tip with a modem _without_ dc, at least
> under NetBSD.  The error you see is from getting an I/O error because
> carrier isn't asserted.

Now that you reminded me, I do recall that a while back nebsd's tty
handling changed to require all programs to jump through a bunch of
hoops when opening an outgoing tty connection.

I grumbled alot to myself and ended up adding a bunch of ioctl() crap
around open() on all my home-grown tty-frobbing programs (for gps,
camera, ups).  At least in those devices the DCD comes up right away
since its just looped back.  One can just open() with O_NONBLOCK and
then immidiately turn around and blow nonblocking io off again with
"fcntl(fd, F_SETFL,0)" and things would just work.

When talking to a real modem the hoops are a bit more involved.  I
guess I could in the PPP case add something to chat(1) so that the
user could turn off the phony DCD from the chat script.

    ABORT "NO CARRIER"
    ABORT "NO DIALTONE"
    ABORT "NO DIAL TONE"
    ABORT "ERROR"
    ABORT "NO ANSWER"
    ABORT "BUSY"
    ABORT "Incorrect"
    TIMEOUT 1
    ""  AT
    OK AT&FE0V1&C1&D2S95=47S0=0 
    TIMEOUT 120
    OK ATDTW12005551212"
    CONNECT \c
    LOCALDCD OFF

I really hate the idea of PPP not being able to immidiately tell that
the modem got disconnected.

> I always thought those disks parked during a spindown.  I never really
> worry about it, actually :-)

I think "park" is a metaphorical description carefully designed to
distract you from thinking about the belly-slide they really do across
some disposable part of the platter.  (If airplanes parked the same
way, everyone would take the train. ;-))

-wolfgang
-- 
Wolfgang Rupprecht    <wolfgang@wsrcc.com>     http://www.wsrcc.com/wolfgang/
DGPS signals via the Internet  http://www.wsrcc.com/wolfgang/gps/dgps-ip.html