Floppy Disk Drive

Front view 3.5-inch floppy disk drive

3.5-inch floppy disk

Rear view of floppy disk drive

Power cablePower cableData cableData cable

How Floppy Disk Drives Work

Read/write headsRead/write heads

360 RP

M

Connectors for a Typical Floppy Disk Drive

Disk driveDisk drive

Power connectionPower connection

Data connectionData connection

34-pin ribbon cable34-pin ribbon cable

Optical DrivesAn external DVD drive

A CD-R disc

An internal CD-ROM driveAn internal CD-ROM drive

Connectors for a Typical CD-ROM Drive

JumpersJumpers Molex power connectorMolex power connectorAudio out Audio out 40-pin connectors40-pin connectors

CD-ROM drive CD-ROM drive

Common Problems with Optical Drives

Misaligned case Tray out of balance Drive mechanism won’t pull disc or tray in CD drive won’t release the CD Disconnected wires Driver problems Overheating Software Default audio device not set to system’s

audio device

Cartridge Drives

External Jaz cartridge drivewith cartridge inserted

Rear view of SCSI externalZip drive

Zip cartridge

How Removable Cartridge Drives Work

3000 RPM

HubHub

Read/write headsRead/write heads

Name Description

SparQA 1 GB cartridge for PCs with a parallel port or EIDE interface. The speeds are equivalent to most hard disks.

SyJet

A 1.5 GB cartridge for PCs and Macs. Interface choices include parallel port, and internal and external EIDE and SCSI. Macs can only use the SCSI version. Seek time is 12 ms and average transfer rate is 6.9 MB per second.

Syquest Drives

Zip Drives

Slightly larger and twice as thick as a regular 3.5-inch disk.

The Zip drive can only read Zip disks. Along with the original 100 MB Zip disk,

currently there are 250 MB and 750 MB versions.

Iomega’s Zip drives can be used in both PCs and Macs.

Connection options now include external USB, FireWire, parallel, and SCSI; as well as internal ATAPI.

Jaz Drives

Comes in 1 GB and 2GB versions. The 2 GB drive can also read 1 GB

cartridges. Considered a legacy drive as it is no

longer manufactured. Currently the Iomega corporation only

supports the 2 GB internal SCSI and external Ultra SCSI models.

Can be used in both PCs and Macs.

SuperDisk Drives

Uses super-high-density floppy disks formatted in a servo pattern with 2,490 tracks.

120 MB capacity per disk. Can also read regular 1.44 MB floppy

disks. Available with parallel port, SCSI, USB,

internal, and PCMCIA connections.

Backup Considerations

What backup media will you use? Does the system give you the

performance and reliability you need? Is the system flexible and easy to use? In the event of a disaster, will the

recovery be complete? How fast can the system be up and

running again?

Tape Drive

How Tape Drives Work1. The computer reads the file system table on the hard drive, locates

the files that you want to back up, and begins reading file data into RAM.

2. Data is then dumped from RAM to the tape drive controller buffer as memory fills.

3. The controller sends commands to the drive to start spooling the tape.

4. The capstan in the center of the supply reel turns the rollers in the cartridge. The belt around the tape and the rollers provide resistance and keep the tape taught and tight to the drive heads.

5. Data is sent from the controller to the read/write heads.

6. The tape is composed of parallel tracks. Data is written from the center out toward the edge on each pass. Holes in the end of the tape signal when the direction of the tape needs to be reversed.

When it gets to the end, it reverses and moves out one track.

The Grandfather Backup Method

Month-ending tape: 12 media sets for each month, rotated every year.

Day-ending tape: 4 media sets for each day,Monday through Friday, rotated every week.

Week-ending tape: 4 media sets for eachFriday of the month, rotated every month.

The Tower of Hanoi Backup Method

Day

Me

dia

Se

t

Media Set Used Every

A 2 days

B 4 days

C 8 days

D & E16 days alternating between set D and E

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

A A A A A A A A

B B B B

C C

D

E

Relative Time to Back Up Data

Am

ount

of d

ata

Am

ount

of d

ata

100%

50%

Am

ount

of d

ata

1 2 3 4 5

Full BackupFull Backup

1 2 3 4 5 1 2 3 4 5

DifferentialDifferential IncrementalIncremental

100%

50%

100%

50%

Common Problems with Internal Removable Media Devices

If the computer case is not properly aligned with the chassis, the opening for the internal drive might be difficult to access.

Because there are large openings in the case for these devices, it is common for them to gather large amounts of dust, so be sure to keep them clean.

Be sure to properly store the media so it is not dirty or damaged. Using dirty or damaged media can damage the drive.