Posted: Mon Mar 18 09:04:14 1985
Date-Received: Wed, 20-Mar-85 04:48:06 EST
A while ago, someone asked about break keys; here's how I've done it:
Hook up a SPDT switch with - common on modem's pin 3 - normally
closed on computer's pin 2 (TxD) (This would normally be connected to
the modem's pin 3) - normally open on pin 20 (DTR) of both computer and
Depressing the switch will then pull the TxD line low for about 1/3
second, which is the standard break signal. I have had absolutely no
problems from this set-up with my Franklin Ace 1200 and Rixon R212A
modem.I understand that it may be wise to add resistors, but since I
wasn't sure of the values I didn't; the electronics have survived thus
far. Also, you may find it helpful to use a terminal block to make the
connections, and use alligator-clip wires at first.
A software method I have heard of but not tried is to send a few nulls with the baud rate turned down to about 5 or so.
-- Jeff Guerber (JGuerber.FSOEP at HIS-PHOENIX-MULTICS)