The Evolution of Storage Devices

The invention of the computer really marked the starting of new era in human life style. It not only made the work simple and easy, but it stored the data in a highly secure manner. In the initial stages the storage devices were mostly based on magnetic elements.

Magnetic storage was first suggested by Oberlin Smith in 1888. The first working magnetic recorder was invented by Valdemar Poulsen in 1898. In 1928, Fritz Pfleumer developed the first magnetic tape recorder. Early magnetic storage devices were designed to record analog audio signals. Modern magnetic storage devices (Floppy, Tapes, Zip drives, etc) are designed for recording digital data.

Optical discs were released to overcome the drawbacks of the magnetic storage devices. CD's were released initially at the first phase which had a storage capacity of 700 MB. High sensitive laser beams were used for writing the data over this media. Red Laser beam is used for reading and writing the CD.

In the second phase of the optical storage devices the DVD's were introduced. It used Laser Beam of much smaller wave length. A single layer DVD can hold data up to 4.7 GB and double layer DVD can hold data up to 8.5 GB. These DVD created a new scope for entertainment media giving it a new digital dimension in entertaining people.

Successively a much superior version of DVD came into the lime light. It was named as blue ray disc. It can hold data up to 25 GB in a single layer disc and 50 GB in a Dual layer disc. As the name indicates this blue ray disc uses blue laser beam for read/write operations.

Holographic Versatile Disc (HVD) is designed to overcome all these digital optical storage media. This HVD is a next generation storage medium which can hold data up to 3.9 Tera Bytes. It has data transfer rate up to 1 GB/sec. It uses two laser beams. The Green Laser Beam is used for reading/writing the data and the Red Laser beam is used to addressing /positioning the data. A single disc costs around US $120-180, although prices are expected to fall steadily in the near future. This optical storage medium is still under research sector for further enhancement in its technology.