dongle-disk

/don'gl disk/ n. See dongle; a `dongle-disk' is a floppy disk which is required in order to perform some task. Some contain special coding that allows an application to identify it uniquely, others *are* special code that does something that normally-resident programs don't or can't. (For example, AT&T's "Unix PC" would only come up in root mode with a special boot disk.) Also called a `key disk'.