The original Lisa, or Lisa 1, has two Apple FileWare 5.25-inch double-sided variable-speed floppy disk drives, more commonly known by Apple's internal code name for the drive, "Twiggy". They have, for the time, a very high capacity of approximately 871 kB each, but proved to be unreliable and required non-standard diskettes. Competing systems implementing that level of per-diskette data storage had to utilize much larger 8" floppy disks. These disks were seen as cumbersome and old-fashioned for a consumer system. Apple had worked hard to increase the storage capacity of the minifloppy-size disk by pioneering features that Sony perfected shortly after with its microfloppy drives. Although it used a Twiggy in the prototype stage, the first Macintosh was launched the following year with one of the Sony 400 kB 3.5" "microfloppy" floppy disk drives. 1984 also saw the release of the first revision of Lisa, the Lisa 2, which also included a single Sony drive. Apple provided free upgrades to Lisa 1 owners to Lisa 2 hardware, including the replacement of the Twiggy drives with a single Sony. The Sony drive, being only single-sided, could not store nearly as much data as a single Twiggy, but did so with greater reliability. The IBM PC shipped with a minifloppy (5.25-inch) drive that stored even less data, 360K. It stored less data, was slower, and also did not have the protective shell of the Sony microfloppy drive diskettes, which improves reliability.