I remember an article in a french newspaper about the switch settings, but I remember also that it did not describes the switch fonctions exepted the 1.44MB already mentionned and a second one that available or not the STE sound chipset, leaving only the Yamaha in action. The writer did not know what is the use of the others...
May be TT swiches will give some clues but I am sure that the TT switches are not the same as the Mega STE switches. Just because TT as no STE sound chipset. (Am I right ?)