Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

ON Keyword - Different Uses
 
The ON keyword is used in various statements to trap events:
Specifies a trap          Type of event                    Enables the trap
◄ON COM(n)►         events on communications port n          ◄COM(n) ON►
◄ON KEY(n)►         a keystroke on key n                     ◄KEY(n) ON►
◄ON PEN►            lightpen events                          ◄PEN ON►
◄ON PLAY(n)►        less than n notes in music buffer        ◄PLAY ON►
◄ON STRIG(n)►       events on joystick trigger n             ◄STRIG(n) ON►
◄ON TIMER(n)►       timer events                             ◄TIMER ON►
◄ON UEVENT►         user-defined events                      ◄UEVENT ON►
 
Other uses of the ON keyword are:
◄ON ERROR► - to enable error handling and specify the error-handling routine
◄ON...GOSUB► - to branch to one of a list of subroutines
◄ON...GOTO►  - to branch to one of a list of line labels