MacTerminal 3.0: How To Send "Break"



A customer wants multisession support from MacTerminal 3.0 running on a
Macintosh connected to a DEC terminal server. He needs to be connected to
the LocalTalk network to print during sessions.

His terminals let him use a "break" key to switch between different sessions
that the terminal server is maintaining for the particular terminal.

He wants to be able to watch three sessions at the same time in different
windows on a two-page display.

What is the ASCII code to put a DEC terminal server into a new session?


There is no ASCII code for the BREAK signal. The data line can be in two
conditions:
- MARK (negative voltage, binary 1), or
- SPACE (positive voltage, binary 0).

The data line is normally in MARK condition; it is in the SPACE condition
only while a frame is being transmitted. A longer-than-normal SPACE
condition, around 100 to 600 milliseconds, is used as a special signal known
as a BREAK.

The "Send Break" command in MacTerminal 3.0 sends a long break (3.5 seconds)
across the open connection, which has the same effect as choosing the
corresponding Break key from the keyboard. The "Send Break" command in
MacTerminal 3.0 is under the Sessions menu; its keyboard equivalent is
Command-Y.


Published Date: Feb 18, 2012