85 terms

computers . storage

storage medium
secondary storage; the physical material on which a computer keeps data, instructions, and information
the number of bytes a storage medium can hold
storage device
the computer hardware that records and/or retrieves items to and from storage media
the process of transferring data, instructions, and information from memory to a storage medium
the process of transferring these items from a storage medium into memory
access time
measures the amount of time it takes a storage device to locate an item on a storage medium; the time required to deliver an item from memory to a processor
transfer rate
the speed with which data, instructions, and information transfer to and from a device; stated in KBps and MBps
magnetic disks
uses magnetic particles to store items such as data, instructions, and information on a disk's surface
the process of dividing the disk intro tracks and sectors
a narrow recording band that forms a full circle on the surface on the disk
pie-shaped sections, which break the tracks into small arcs
the smallest unit of disk space that stores data and information; each cluster holds data from one file
allocation unit
consist of two to eight sectors
you can remove the medium from one computer and carry it to another
hard disk
a storage device that contains one or more inflexible, circular platters that magnetically store data, instructions, and information
fixed disk
a hard disks that is mounted inside the system unit and is not portable
longitudinal recording
which aligned the magnetic particles horizontally around the surface of the disk
perpendicular recording
hard disks align the magnetic particles vertically; and provide 10x storage capacity
affects the capacity of the hard disk; made of aluminum, glass, or ceramic and i coated with an alloy material that allows items to be recorded magnetically on its surface
form factor
size of the platter
read/write head
the mechanisms that read items and writes items in the drive as it barely touches the disk's recording surface
the vertical section of a track that passes through all platters
revolutions per minute
measures the rate of which the had disks rotates; allows nearly instant access to all tracks and sector on the platters; each platter is about 5,400 to 15,000 rpms
head crash
occurs when a read/write head touches the surface of a platter, usually resulting in a loss of data or sometimes loss of the entire drive
a duplicate of a file, program, or disk placed on a separate storage medium that you can use in case the original is lost, damaged, or destroyed
disk cache
buffer; consist of memory chips on a hard disk that stores frequently accessed items such as data, instructions, and information
the number of bits in an area on a storage medium
RAID (redundant array of independent disks)
a group of two or more integrated hard disks
pocket hard drive
a self contained unit that you insert in and remove from a slot in a device or a computer or plug in a USB port on a computer
miniature hard disk
provide users with greater storage capacities than flash memory, and are smaller than notebook computer hard disks
external hard disk
a separate free standing hard disk that connects with a able to a USB port or Fire Wire port on a system unit
removable hard disk
a hard disk that you inset and remove from a drive
disk controller
consists of special purpose chip and electronic circuits that control the transfer of data, instructions and information from a disk to and from the system bus and other components in the computer
SATA (serial advanced technology attachment)
uses serial signals to transfer data, instructions, and information
EIDE (enhanced integrated drive electronics)
a hard disk interface that uses parallel signals to transfer data, instructions, and information
SCSI (small computer system interface)
uses parallel signals and can support up to 8-15 peripheral devices
SAS (serial attached SCSI)
a newer type of SCSI that uses serial signals to transfer data, instructions, and information
online storage
a service on the Web that provides hard disk storage to computer users, for free or for a minimal monthly fee.
holds data, instructions, and information for further use
memory chip access time
measured in nanoseconds
storage device access time
measured in milli or microseconds
transfer rates
measured in KBps and MBps
benefits of online storage
allows access to files on the internet hard disk from any computer; stores large audio, and video instantly; allows other to access files on their internet hard disk; view time-critical data and images immediately; store offsite backups of data
floppy disk
diskette; a portable, inexpensive storage medium that consists of a thin, circular, flexible plastic Mylar film with a magnetic coating enclosed in a square-shaped plastic shell
floppy disk drive
a device that reads and writes from a floppy disk
external floppy disk
the drive is separate device with a cable that plugs in a port on the system unit
optical disc
a type of storage media that consists of flat, round, portable disc made of metal, plastic, lacquer that is written and read by a laser (4.75 in. diameter--but mini optical disc are 3 in. in diameter)
magnetic media
optical media
light scribe technology
works with specifically coated optical discs, to etch labels directly on the disc
compact disc read-only memory; a type of optical disc that users can read but not write or erase; holds 650 MB to 1 GB
single session disc
manufacturers write all items on one time
CD-ROM drive
CD ROM player
compact disc-recordable; a multisession optical disc on which users can write, but not erase, their own items such as text, graphics, and audio
multisession disc
you can write on part of the disc at one time and another part in a later time
CD-R drive
reads both audio CDs and standard CD-ROMs
compact disc rewritable; is an erasable multisession disc you can write on multiple times
the process of writing on an optical disc
the process of copying audio and/or video data from a purchased dic and saving it one digital media
archive cd
stores photos from an online photo center in the jpg file format, usually at maximum resolution of 7200 pixels per photo; it cost $7 per hundred photos
picture cd
a single session CD-ROM that stores digital versions of film using a jpg file format at a lower resolution; which cost $3 per roll of film
video CD
(VCD) is a CD format that stores video on a CD-R that can be played in CD or DVD drives, many DVD players, and some game consoles
digital versatile disc-read-only-memory; a high capacity optical disc on which users can read but not write or erase
Blu-ray disc
has storage capacities of 100GB, with expectancies of exceeding 200GB in the future
versatile multilayer disc; potentially will contain 20 layers with 5 GB each
mini-DVD, that stores up to 1.8 GB of games, movies, or music
three competing DVD formats
a magnetically coated ribbon of plastic capable of storing large amounts of data and information at a low cost
tape drive
reads and writes data and information on a tape
tape cartridge
a small, rectangular, plastic housing for a tape
tape library
tape cartridges are mounted in a separate cabinet
sequential access
reading or writing data consecutively in tapes
direct access
random access; the device can locate a particular data item or file immediately, without having to move consecutively through items stored in front of the desired data item or file
PC card
used to add memory, storage, and communications to the computer; thin, credit-card sized removable flash memory device that fits into a PC card slot
express card
used to add memory, storage, and communications to the computer;removable device, smaller than a pc card, that fits in an express card slot
personal computer memory card international association; which created express and pc cards
solid state media
a flash memory card that consist entirely of electronic components and contain no moving parts
common types of flash memory cards
compact flash (CF), secure digital (SD), micro SD, xD Picture Card, and memory stick
card reader/writer
a device that reads and writes data, instructions, and information stored on flash memory cards
USB flash drive
pen drive, thumb drive; storage device that plugs in a USB port on a computer or a mobile device
U3 smart drive
offers even more convenience than a flash drive, because it includes pre-installed software accessed through a Windows type interface
smart card
similar in size to a credit card or ATM; stores data on a thin microprocessor embedded in the card
a 100 to 215 foot roll of film
a small sheet of film, usually about 4 x 6 images
computer output microfilm recorder
the device that records images on the film