CHAPTER 10
MAGNETIC DISK STORAGE
INTRODUCTION
Probably the most used storage medium today is the magnetic disk. Disks and
disk drives come in a variety of sizes and types. Diskettes (floppies or floppy disks)
are used in personal computers in offices and make it easy to exchange data between
offices and commands. Disk file units, also refereed to as mass memory units, have
removable hard disk packs and are used with the large mainframe computer systems
such as the Combat Direction System (CDS) and the Shipboard Nontactical ADP
System (SNAP). The fixed disk drives are used extensively in personal computers
and minicomputers such as the Tactical Command System (TCS).
After completing this chapter, you should be able to:
l State the functions of magnetic disk storage devices
l Define random access as used in magnetic disk memory systems
l Describe the different types of magnetic disks
l Define magnetic disk tracks, sectors, and cylinders
. Describe the construction of floppy disks
l Describe the operations of floppy disk drives
l Define disk density and coercivity
l Describe the correct procedure for installing and configuring a floppy
disk drive in a microcomputer
l Describe how MS-DOS organizes data on floppy disks
l Describe the precautions to be followed in handling and storing floppy
disks
. Describe the construction of a disk pack
. Describe the major functional areas of a disk file unit controller
l Explain the functions of the major components of the disk drive unit or
a disk memory set
l Explain how a disk memory set formats a disk, writes data to a disk, and
reads data from a disk
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