Disk Evolution / The Apple IIc Plus
A page at Apple2History.org detailing advances in Apple II disk storage. From the page:
"After Steve Wozniak's Disk II floppy drive changed the Apple II from a hobbyist toy to a serious home and business computer in the late 1970's, progress was slow in improving disk storage for the Apple II series. In 1978, the year the Disk II was released, Mike Scott (Apple's president) and Randy Wigginton were asked at a user group meeting whether they were going to go to the larger capacity eight-inch floppy drives (which had been around before the 5.25 floppy drives were invented). They answered that no, the Apple II was not going in that direction, but felt it might get a hard disk by 1979 or 1980, and possibly earlier than that a double sided, double density 5.25 disk holding 500K per disk"

Disk Evolution / The Apple IIc Plus