E0001 Computers in Engineering

Secondary storage

Readings

Shelly 1999 - Chapter 6Shelly 1997 - Chapter 5Shelly 1995 - Chapter 6Meyer 1997 - Chapter 2BMeyer 1995 - Chapter 2B

Floppy disksHard disksOptical discsMagnetic

Tape

Types of Secondary Storage

Floppy Disks

Tracks and Sectors

Floppy Disk Capacity

3 1/2 inch double sided; double density - 720kB double sided ; high density - 1.44MB

5 1/4 inch double sided; double density - 360kB double sided ; high density - 1.2kB

Storage terms

kilobyte - KB - 1000 bytesmegabyte - MB - 1000 000 bytesgigabyte - GB - 1 000 000 000 bytesterrabyte - TB - 1000 000 000 000

bytes

Care of disks

Head clearance

How a disk drive works

360 revolutions per minuteread-write headsaccess armseek and search operationaccess time

How data is stored

Hard disks

internal diskshard disk cartridgeshard disk packs

Performance Enhancements

disk cachingdata compression and

decompressionRAIDS - redundant arrays of

inexpensive disks (RAIDs)

RAID system

Optical discs

650 MB of datalaser beamthree kinds

CD-ROM CD-R erasable optical discs

Magnetic Tape

Streamers cartridge unit digital audiotape (DAT)

Reels