VT100.net VT102 User Guide
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Table 1-1 Keyboard Locked Condition
Cause Method of Clearing
Terminal not connected to computer. Communication line signals are not correct for communication. Cleared when a connection exists between computer and terminal. Check CTS and DSR indicators to determine if a connection exists.
Half-duplex communication is selected (by modem control SET-UP feature) and terminal is receiving characters. Terminal cannot transmit characters when receiving characters in half-duplex. Cleared when line turns around and terminal can transmit characters.
Characters are typed into terminal faster than they can be transmitted. Cleared when terminal transmits characters in keyboard character buffer to computer.
A print operation selected while offline. Cleared when print operation ends.
Computer turns off keyboard. Computer turns on keyboard.

NOTE: Entering and exiting SET-UP with KBD LOCKED on erases the keyboard character buffer and cancels printing or print operation requests.
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