1. By Michael Lum Period 9

2. Optical Media Optical Drives allows people to store files The files can be put onto CD’s, DVD’s and Blue Ray Discs.

3. Optical drives were invented by David Paul Greg in 1958 The Phillips Consumer Electronics improved the technology throughout the 1960s.

4. Compact Disks (CDs) CD’s were invented in 1982 and had 120 mm in diameter They could store up to 700 megabytes of data. Original CD-ROMs (CD-Read Only Media) and were read-only, non-modifiable discs.

5.  CD - RWs ( CD - Rewritable ) were introduced in 1997 and could be overwritten.  Their life expectancy was 2 years, in contrast to the CD - ROM ’ s 30 years.  Eventually, the CD - ROMs were replaced by DVD - ROMs.

6. DVDs (Digital Versatile Discs) First DVD invented in 1993 Higher capacity than CDs

7. DVD+R (DVD+Recordable)) In 1997, DVD-R (DVD-Recordable) was invented Had capacity of up to 8.5 GB Memory on it cannot be erased

8. DVD-RW (DVD-Rewritten) Invented in 1999 Had memory of 4.7 GB Could have memory erased and written about a thousand times

9. Blu-Ray Disc Appeared on market in 1998 from Sony Dual layered discs have 50 GB More expensive ($40) More popular