boot disk

operating system The magnetic disk (usually a hard disk)

from which an operating system kernel is loaded (or

"bootstrapped"). This second phase in system start-up is

performed by a simple bootstrap loader program held in ROM,

possibly configured by data stored in some form of writable

non-volatile storage.

MS-DOS and Microsoft Windows can be configured (in the

BIOS) to try to boot off either floppy disk or harddisk, in either order. By default they first check for the

presence of a floppy disk in the drive at start-up and try

to use that as a boot disk if present. If no disk is in the

drive they then try to boot off the hard disk.

Some operating systems, notably SunOS and Solaris, can

be configured to boot from a network rather than from disk.

Such a system can thus run as a diskless workstation.

(1997-06-09)