ICT
Chapter:3 storage devices and media
Magnetic tape drivers
Uses:
 Used as a backup media
 Used in long term archiving data
Adv:
 Less expensive
 Huge data storage
 Very robust
Dis adv:
 Affected by magnetic fields
 Very slow data access time
Hard disk drives
Uses of fixed:
 Storing application software
 Used in real time systems
Adv:
 Very fast data transfer
 Large memory capacities
Dis adv:
 Fairly easily damaged
 Have many moving parts which affect their reliability
Portable hard disk drives
Uses:
 Used as a backup system
 Used to transfer data/softwares/files between computers
Adv:
 Large memory capacity
 Data access rate and transfer rate is fast
Dis adv:
 Easily damaged
 Data transfer rate not fast as fixed hard disk
CD/DVD
Uses of cd-r and DVD-r:
 Home recording of music and movies
 Used to store data for later use
Adv of cd-r and DVD-r:
 Cheaper medium
 Behave like ROM once burned
Dis adv of cd-r and DVD-r:
 Only record once
 Not all cd or dvd can read cd-r or dvd-r
Uses of cd-rw/DVD-rw:
 Used to record television programmes
 Used in cctv systems
Adv of cd-rw/DVD-rw:
 Written over many times
 Can use different file formats
Dis adv of cd-rw/DVD-rw:
 Can be expensive
 Accidentally overwrite data
Uses of cd-rom and dvd-rom:
 used to store music files
 Have much larger storage
Adv of cd-rom/DVD-rom:
 Less expensive
Dis adv of cd-rom and dvd-rom:
 Data transfer rate is slower then any hard disk
Uses of
disk:
 Home
 Storing
back
Disk type Laser wavelength Disk
Track
colour
construction pitch
Cd
Red
780nm
Single 1.2
1.60um
mm
DVD(dual) Red
650nm
Two 0.6 mm 0.74um
BluBlue 405nm
ray(single)
ADV of
Blublue 405nm
disk:
ray(dual)
 Very large storage capacity
 Very fast data transfer
Dis adv of blu-ray disk:
 Expensive
Single 1.2
0.30um
mm
Two 0.6 mm 0.30um
blu-ray
video console
and playing
movie
blu-ray
 Encryption problems
Solid state drives
ADV:
 More reliable
 Considerably lighter
 Low power consumption
 Very thin as no moving parts
Dis:
 Not used in all servers
Pendrives
Uses:
 Transporting files
 Security device to prevent software privacy
Adv:
 Very robust
 Very compact and portable
 Not affected by magnetic fields
Dis:
 Easy to lose
 Incorrect remove from the laptop can corrupt all data
Memory cards
 Sd
 XD
 Cfast
Uses:
 Storing photos on digital camera
 Used as mobile phone memory card
Adv:
 Very compact
 Very durable
 Hold large amount of data
Dis:
 Expensive per gigabyte
 Can be lost, stolen or damages
 Not all computers have memory card readers built in