Macintosh SE FDHD (1989)
Originally the SE could use only Single Sided Double Density (SSDD) (400 KB) and Double Sided Double Density (DSDD) (800 KB) formatted floppy disks. In August 1989, Apple introduced the Macintosh SE FDHD with the new SuperDrive, a floppy disk drive that could handle 1.4 MB High Density (HD) floppy disks. Originally marketed as FDHD (Floppy Disk High Density"), later some Macintosh SE FDHDs were labeled Macintosh SE Superdrive, to conform to Apple's marketing change with respect to their new drive. HD floppies would become the de facto standard on both the Macintosh and PC computers from then on. An upgrade kit was sold for the original Macintosh SE which included new ROM chips and a new disk controller chip, to replace the originals. The SE FDHD was discontinued in October 1990, with the introduction of the Macintosh Classic to succeed it.
via Wikipedia: http://en.wikipedia.org/wiki/Macintosh_SE#Macintosh_SE_FDHD