AT&T 610 User Manual page 72

Operations
Page 6-10
lfed:la Copy
User .... s Guide
August 1985
The line can send to the printer without sending to the
display by using the Media Copy escape sequences. The sequence
ESC [5i received on line will put the terminal into the Media
Copy mode. Receiving the sequence ESC [4i will cause the terminal
to leave the Media Copy mode. When Media Copy is on, all data
sent to the terminal is sent directly to the printer and is not
displayed.
If the send parity option is se t to "none", all 8 bits of
data are sent to the printer; otherwise, the 8th bit is sent as
space. The keyboard is active during Media Copy. Data echoed
to the terminal (local or remote) is sent directly to the
printer.
When Media Copy is on, an "mc" indicator appears on line
26
between the screen--labels for F3 and F4. Media Copy overrides
Print On-Line.
Media Copy is terminated when the line disconnects or
Set-Up is entered.