الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Bigger, better, faster, smaller, cheaper, and more flexible....these features are at the top of every system designer`s wish list.
Occupying a critical position in the systems to come are mass storage device. Their charter is to supply both the massive amount of data storage capacity and the rapid access to data that these systems will require.
In this thesis, I will make a survey on mass storage devices which some of which depends on magnetic storage and the other depend on optical storage, magnetic storage devices based on magnetic effect where the storage media is a magnetizable surface and retains the information presented to it by write heads, the read heads convert the stored information back to electrical form but optical storage systems based on light rather than magnetism, it utilize a highly focused laser beam to record information. This technology offer very high storage density with very high data rates, rapid random access to the data potential archival properties and a projected low media cost Examples of these mass storage devices are: Drum memory, bubble memory, magnetic tape, hard disk, flopy disk, and optical memory.
The thesis is organized as follow: In chapter 1, is introduction which contains a historical background on memory and defintions of types of mass storage devices.
Chapter 2, explain the main principles on magnetic storage and how the information written on or read from the disk, also it explains the magnetic recording techniques and varied drive interfaces.
Chapter 3: is the drum memory and magnetic bubble memory. Firstly, Imade a historical background on these and explained a magnetic drum. Alao, Iexplained a magnetic bubble memory and how information stored in it and read fromit. Finally, Imade a comparison between a bubble memory and othermemory types and illustrating a bubble memory market.
In chapter 4, is a magnetic tape. Imade a historical background on magnetic tape and explai the tape system and cartridges, finally Iillustrate the digital audio tape and how it can be rise the capacity where it is reach to 2.3 GB on 8mm.
In chapter 5, is the hard disk, Also in which Imade a historical background on it and illustrate its construction,its maintenance software. Finally, I explain the new technique to increase the density which is breaking the data with array of small drives where 100 small disks which stores 10 GB compared with one large disk which stores 7.5 GB, also this array decrease the cost and access time.
In chapter 6, is the floppy disk, in which I made a historical background and I explained a floppy disk, finally I illustrate a new floppy disk with 2-in which appears in 1990.
In chapter 7, is the optical memory, in which I made a historicval background and explained the main types of optical memory (i.e OROM, WORM, and erasable memory ), Finally I illustrate the optical strage news and its new developments.
In chapter 8, I maked an improvment in disk subsystem acces time which will this time reduced by approximately 405 of the system measured by using seek overlap technique.