Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
Nodes       : 899
Index Size  : 28056
HCP-Version : 3
Compiled on : Atari
@charset    : atarist
@lang       : 
@default    : Document not found
@help       : Help
@options    : +g -i -s +z
@width      : 75
@hostname   : STRNGSRV
@hostname   : CAB     
@hostname   : HIGHWIRE
@hostname   : THING   
View Ref-FileON BREAK
ON BREAK CONT
ON BREAK GOSUB proc

proc: procedure name

These three commands control the response to the simultaneous pressing of the
Control, Shift (left shift-key only), and Alternate keys. Normally, pressing
this key combination causes the termination of a program but, it can also be
used to call a particular procedure. To do this, the procedure to be called is
defined by means of the instruction ON BREAK GOSUB proc.

When an ON BREAK CONT is present in a program, the Control, Shift, and
Alternate key combination is deactivated. An ON BREAK reactivates this key
combination once again.

Example:

    ON BREAK GOSUB test
    PRINT "Press CONTROL, SHIFT, (the left one) and ALTERNATE"
    DO
    LOOP
    '
    PROCEDURE test
      PRINT "that was it"
      ON BREAK
    RETURN

--> The request to press the key combination is displayed. When they are
    pressed, the procedure 'test' switches the normal BREAK routine on again.

Memo: Return code will be -128 if the program is stopped (compiled).

      For compiler related options see sections 'Interrupt Routines' and
      'Checking the BREAK keys, EVERY and AFTER'.

      If the procedure used with ON BREAK GOSUB is undefined the compiler will
      not issue an error message. Instead the compiler writes a bad binary
      where ON BREAK GOSUB is translated into JSR 0.l!

      The editor does not report a missing procedure with ON BREAK GOSUB.