Also, while this will free all graphics in Blitz Basic (2d) and Blitz3D, it won't work for all images in BlitzPlus. this is because you can load some images to video mem and some to system mem in Blitz+, and only the video memory ones get cleaned out on a graphics mode change.
Of course, that may be irrelevant to you dependent on what version of Blitz you're using now - although you might want to keep your code future-proofed in case you do upgrade.
Of course, that may be irrelevant to you dependent on what version of Blitz you're using now - although you might want to keep your code future-proofed in case you do upgrade.