1. 1 CP586 © Peter Lo 2003 Multimedia Communication Multimedia Storage

2. CP586 © Peter Lo 20032 Types of Media Magnetic Media Suitable for dynamic data that often changes. Used in most cheap portable floppy disks an hard disk drives. Optical Media Optical media such as the CD has a long life span and high storage capacity. Fast data access times. Analogue Media Videodisk is the general term for disks used to store analogue data.

3. CP586 © Peter Lo 20033 The Evolution of Storage Storage began as a series of punch cards. Eventually secondary storage devices and hard disks were required to store data. Magnetic media was used to store data. Advances in optical technology lead to the development of CD ROM and DVD technology.

4. CP586 © Peter Lo 20034 Compact Disk A CD is a polished metal platter capable of storing digital information and is used in the music industry to store digital recordings. CD’s are read-only, which means that once the data has been recorded onto them, they can only be read, or played. The standard for most CD-ROMs is 24 or 32 speed (24 times per second).

5. CP586 © Peter Lo 20035 Compact Disk Read Only Memory (CD ROM) A CD ROM can store up to 1GB, although the most common size is approx 630MB. A single CD-ROM has the storage capacity of 700 floppy disks, enough memory to store about 300,000 lines of text.

6. CP586 © Peter Lo 20036 DVD Short for digital versatile disc or digital video disc, a new type of optical technology that holds a minimum of 4.7GB (gigabytes), enough for a full-length movie. Many experts believe that DVD disks, called DVD-ROMs, will eventually replace CD-ROMs, as well as VHS video cassettes and laser discs.

7. CP586 © Peter Lo 20037 DVD Specifications The DVD specification supports disks with capacities of from 4.7GB to 17GB and access rates of 600KBps to 1.3 MBPS. DVD drives are backward-compatible with CD-ROMs. DVD players can play a CD-ROM, CD-I disks, and video CDs, as well as new DVD-ROMs. DVD is 5” or 12 cm in diameter.

8. CP586 © Peter Lo 20038 DVD Specifications With DVD, information is contained in pits which are about half the size of CD pits and the tracks are therefore twice as close together. DVD can store 7 to 14 times that of a CD. Up to 8 different language soundtracks and 32 different language subtitles can exist on one DVD.

9. CP586 © Peter Lo 20039 DVD Features Multiple camera angles. (Eg. 007) Parental Lock or rating control. Multi-aspect ratio : Letter box or wide screen. Interactive movie plots. (Eg. Blade) Multiple Soundtracks and sub titles. Additional footage and voiceovers.

10. CP586 © Peter Lo 200310 (Write Once Read Many Times) WORM This technology allows you to write data to a disk a single time. However, after that the data is permanent and can only be read many times. Unlike CD-ROMs, there is no single standard for WORM disks. As a result you need the same hardware to read and write.

11. CP586 © Peter Lo 200311 Tape A magnetically coated strip of plastic on which data can be encoded. In the computing industry tapes are primarily used for backup because information has to be accessed sequentially rather than randomly. Tape drives are now available for PC’s at a relatively inexpensive cost. (DAT)

12. CP586 © Peter Lo 200312 Removable Hard Disk Often HDD are enclosed in plastic or metal cartridges so that they can be removed like floppy disks. The storage capacity of a typical removable hard disk can range from 60MB to 2GB, much more than the capacity of floppy disks.

13. CP586 © Peter Lo 200313 Iomega Zip Drive Iomega Zip drive uses a low-cost, flexible- magnetic-media technology that gives it a decided price advantage over drives that use SyQuest and magneto-optical technology. A Zip disk is light and easy to carry. However, these disks are fairly slow and do not compare to the read performance of a CD ROM. The Zip Plus can hold 250MB.

14. CP586 © Peter Lo 200314 Iomega Jaz Drive A removable disk drive developed by Iomega Corporation. The Jaz drive has a 12-ms average seek time and a transfer rate of 5.5Mbps. The removable cartridges hold 1GB of data. The fast data rates and large storage capacity make it a viable alternative for backup storage as well as everyday use.