chapter 3 storage

Random and Sequential Access

Random

file

filename

folder

Random

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Random

Optical Discs

representation data on it

optical drivers

Storage Media and Storage Devices

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Storage medium: - the part of a storage system where data is stored , such as a DVD disc.Storage device:- a pice of hardware sucha as a DVD drive

Storage System Characteristics

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All storage system have specific characterstic inclusing storage medium and a storage devic, portability and volatility.

Type of Storage Technology Used

hard drive

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: is a primary storeage system for most computers used to store most programs and data used with a computer

magnetic hard

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Traditional hard drivers are magnatic hard drivers that contain magnatic hard disks /read wite heads, and acess mechanism.

solid state drivers

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A hard drive that uses flash memory media instead of metal magnatic hard disk and magnetic technology. are an especially attractive option for portable computer or mobile devices

Internal and External Hard Drives

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Internal hard drivers are located inside a computer system unit and are not removed unless there is a problem.due to a large capacity , full sized external hard drives which are magnatic hard drives and hold between 500 GB and 4 recorded TVshows.

Read-Only Discs

CD-ROM

DVD-ROM

BD-ROM Discs

Volatility

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Conventional RAM is volatile so programs and documents held in RAM are erased when they are no longer nedded by the computer or when a power turned off.

Rewritable Discs

CD-RW, DVD-RW, DVD+RW

BD-RE Discs

Flash Memory

Flash Memory Cards

USB Flash Drives

USB Flash Drives

Recordable Discs

CD-R,

DVD-R

BD-R Discs