Sizes
Different sizes of floppy disks are fundamentally incompatible, and disks can fit only one size of drive. Drives with 3 1⁄2-inch and 5¼-inch slots were available during the transition period between the sizes, but they contained two separate drive mechanisms. In addition, there are many subtle, usually software-driven incompatibilities between the two. 5 1⁄4-inch disks formatted for use with Apple II computers would be unreadable and treated as unformatted on a Commodore. As computer platforms began to form, attempts were made at interchangeability. For example, the "Superdrive" included from the Macintosh SE to the Power Macintosh G3 could read, write and format IBM PC-format 3½-inch disks, but few IBM-compatible computers had drives that did the reverse. 8-inch, 5 1⁄4-inch and 3 1⁄2-inch drives were manufactured in a variety of sizes, most to fit standardized drive bays. Alongside the common disk sizes were non-classical sizes for specialized systems.
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