Rocket 204 - ON ATTENTION Statement

12 Rocket Model 204 Terminal User’s Guide
Attention interrupt feature
ON ATTENTION statement
In User Language, an ON ATTENTION statement can be specified in a request.
Through this statement, the user specifies the action that Model 204 takes (that
is, the flag to be set or the branch to be executed) when an end user invokes
an attention interrupt.
If an ON ATTENTION statement has been specified, and the attention key is
pressed while Model 204 is evaluating a User Language request and not
performing I/O to the terminal, the operation specified in the ON ATTENTION
statement is performed.
If no ON ATTENTION statement has been specified, the action Model 204
takes when the attention key is pressed depends upon the operation being
performed at the terminal. The following list summarizes the actions that are
possible.
Model 204 responses to the attention key are:
• If the attention key is pressed at any terminal when the user is entering a
system control command or an Editor command, the current input line is
ignored and the command is not executed. The user can reenter the
command or statement. However, if an editor command has been
completely entered at the time of the attention interrupt, the attention key
has no effect on editor operations.
• If the user presses the attention key when entering an ad hoc request,
Model 204 stops compilation and returns to command level.
• If the user presses the attention key while a procedure is compiling,
Model 204 flushes the procedure and returns to command level.
• If the user responds to a dummy string prompt by pressing the attention
key, and if an ON ATTENTION statement has not been specified,
Model 204 terminates compilation, ends all procedures, and returns to
command level.
• If the attention key is pressed in response to a $READ or $ENTER prompt,
and if an ON ATTENTION statement has not been specified, the current
request is aborted. Model 204 ends all procedures and returns to command
level.
• If the user is entering a procedure after typing a PROCEDURE command,
Model 204 treats the attention interrupt as an END PROCEDURE
statement. Model 204 does not expect the user to enter additional
statements, but the statements that already have been entered are saved.
• If the user is at the pause point on a 3270-type terminal, and if an ON
ATTENTION statement has not been specified, the attention key cancels
output from the current request. If a procedure is being executed,
Model 204 flushes all input lines in the procedure and returns to command
level.