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From: mm3d+@andrew.cmu.edu (Matt McNally)
Newsgroups: comp.sys.mac.programmer
Subject: I need a 'Break'...no really.
Message-ID: <8ZErPKm00UhWM2olYY@andrew.cmu.edu>
Date: 23 Oct 89 20:38:46 GMT
Organization: Computing Systems, Carnegie Mellon, Pittsburgh, PA
Lines: 31


Does anyone have any experience with sending an actual
'Break' through the serial ports?  Although IM-II defines
a 'Break' as when "the line is held in the 'space' state 
for one frame or longer", I have yet to discover exactly
how I can acomplish this feat.

Any help would be extremely appreciated.

Matt

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'Macintosh II Project' Research Programmer/Dugan
Carnegie Mellon, H&SS Dean's Office, Pittsburgh, PA 15213
Office: Baker Hall 369-B, (412) 268-6990

ARPANET Address: mm3d@andrew.cmu.edu
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For those who are interested, here's why...
 
We have built a really simple router that allows us to
'focus' the serial line to any of eight devices. But in
order to set the 'focus' mask I need to send a 'Break'
to the router to let it know I'm changing the focus
instead of actually sending a data character through.

Although we could use the serial drivers 'break mode'
by changing the hardware, we would really like to
use a 'Break' as this keeps the hardware down to a
bare minimum.