Lightpen statements

INPEN X,Y

Reads the x,y coordinate of the lightpen. X,Y are set to -1 if the lightpen is not detected.

INPUTPEN X,Y

Reads the x,y coordinate of the lightpen at the time the lightpen button is pressed. X,Y are set to -1 if the lightpen is not detected.

PTRIG

This function indicates the state of the lightpen interrupt.

TUNE

For tuning the lightpen