G90 ;Absolute programming
G21 ;Programming in millimeters (mm)
M5  ;Disable laser
G1 X0.1 Y0.1
M3 I S150 ;start laser
G1 X0.1 Y0.1
G1 X9.9 Y0.1
G1 X9.9 Y9.9
G1 X0.1 Y9.9
G1 X0.1 Y0.1
M5 ;stop laser
G1 X0.0 Y0.0; Display printbed
M02 ;End of program