This was made possible as the SuperDrive now utilitized the same MFM (Modified Frequency Modulation) encoding scheme used by the IBM PC, yet still retained backward compatibility with Apple's variable-speed zoned CAV scheme and Group Coded Recording encoding format, so it could continue to read Macintosh MFS, HFS and Apple II ProDOS formats on 400/800 KB disks. This drive was also capable of reading and writing MS-DOS formatted disks and FAT12 file formats, using PC Exchange or other software, unlike the 400 KB and 800 KB drives. This replaced the older 800 KB floppy drive that had been standard in the Macintosh up to then, but remained compatible in that it could continue to read and write both 800 KB (double-sided) and 400 KB (single-sided) floppy disks, as well as the newer high-density floppies. The term was first used by Apple Computer in 1988 to refer to their 1.44 MB 3.5 inch floppy drive. Internal SuperDrive floppy drive on a Macintosh LC II