SHAHID RIAZ

2. SHAHID RIAZ CLASS : BSN 1st year ROLL NO : 2017-043 USB & CD ROM

3. OBJECTIVE….. • ‘USB’ and ‘CD ROM’ Stand for ??? • History of USB • What is USB & CD rom. ? • Types of USB • Advantages of USB • Disadvantages of USB • Conclusion • Reference

4. Stand for…. • USB Stand for “Universal Serial Bus” • CD Romstand for “compact disc read only memory”

5. History of USB…. • A group of seven companies began the development of USB in1994; Compaq, DEC, IBM, Intel, Microsoft,NEC, and Nortel • In Pakistan USB was developed in 2003-4 Sign of USB

6. What is USB?? • The cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices is called ‘USB’ • Capacity of USB is 2 , 4 , 8 , 16 GB • Now a day USB are 100 or more than 100 GB

7. Types of USB…. • Many types of USB are available in world but few of them are : • The older "standard" size e.g. USB flash drives • The "mini" size e.g. such as on many cameras • The "micro" size e.g. Such as on most modern cell phone

8. Advantages of USB… • Storage data • USB are also use as charger because it can transfer 0.5–1.5 A current . • Through USB data transfer easily • Some USB are used as wireless internet such as evo , Wi-tribe etc.

9. Advantages continue… • One can easily remove and add data and information in it • free from scratches and due to small size easy to save and protect it

10. Disadvantages…. • It causes Transfer of viruses from one computer to other ones • It is used for different types negative uses such as stolen of different documents • Due to its small size it is easily misplaced • It is expensive as compared to hard devices • The sudden failure of USB causes many problems

11. What is CD-ROMs • It is used to store data and somehow to transfer data • The CD-ROMs is 1.2mm thick disc of polycarbonate plastic with a layer of aluminum • The size of CD-ROMs is mostly 120mm in diameter with a disc of 80mm diameter • Compact disc capacity is 760 MB in 1.2mm thick disc while now DVDs has a capacity of 4.7GB in a single disc

12. Standards for CD-ROM • Red book developed by Philips and Sony in 1980 • Yellow book developed in 1984 to describe the physical format of a CDs . Its two modes are • CD-ROM Mode 1 used to store with error correction • CD-ROM Mode 2 to store videos and graphical data

13. Standards for Compact disc • Green book physical speciation's for CD-1 • Orange book physical format for writable CDs • Orange book is further divided into three • White book physical format for video CDs • Blue book physical format for extra CDs

14. Modes of CD-ROM • Two basics modes of CD-ROM • CD-ROM Mode 1 used for computer data • CD-ROM Mode 2 used for audio video etc.. • CD-ROM XA Mode 2 form 1 used for computer data • CD-ROM XA Mode 2 for audio video or pictures

15. Advantages of CD-ROM • Capability to store large amounts of information • Ability to store data graphics audio and video on the same disc • The optical head of CD-ROM derive never teach with disc so there is no chance of head crash wear and fear of accidental data loss • Countable or uncountable storage units

16. Disadvantages of CD-ROM • High initial cost to produce a single disc • Slow access and data transfer time compared with high performance fixed disk systems • Easily broken so data may be lost • Require specific derives to read and write • CD-ROM failure is common which causes wastage of time and money

17. conclusion • From above information we have come to know that every thing has negative as well as positive aspects , but USB is very beneficial device for storage of data in short place and it unscratchable device

18. References • www.kiokea.net • www.winbookcorp.com • www.alibiba.com • www.pinterest.com