Presentation is loading. Please wait.

Presentation is loading. Please wait.

GRAP 3175 Computer Applications for Drafting Unit II Computer Hardware.

Similar presentations


Presentation on theme: "GRAP 3175 Computer Applications for Drafting Unit II Computer Hardware."— Presentation transcript:

1 GRAP 3175 Computer Applications for Drafting Unit II Computer Hardware

2 Secondary Storage

3 Nonvolatile storage that is external to the main memory Used for: –Storage of large amounts of data –Permanent or long-term storage –Backups Hardware is input/output (I/O) device

4 Three Secondary Storage Media Magnetic tape Magnetic disks Optical technology

5 Three Main Characteristics How much storage do you need? –Totals bytes –Density How fast do you need it? –Data access time -- milliseconds –Data transfer rate -- megabytes per minute How much will it cost? –Fixed cost –Cost per megabyte

6 Type of Storage Device Local On-line Near-on-line Backup Archival Distribution Hard Disk Server-based magnetic & optical drives Optical jukeboxes & tape changers Tape drives & changers Tape drives & optical disk Floppy disks, recordable CR-ROMS, & magnetic tape

7 Evaluation Criteria Throughput (speed) -- transfer rate Access time (delay) Capacity Drive cost Media cost Archival life

8 Type of Storage Criteria On-line Near-on-line Backup Archival Distribution High throughput, fast access time & high capacity Very high capacity, low media cost, & long archival life High capacity & low drive cost Low media cost & long archival life High capacity & low media cost

9 Magnetic Tape 1/4, 1/2, 4mm, 8mm, or VHS Tape drive (I/O) Sequential Storage Inexpensive -- backup storage

10 Reel-to-reel Tape 21MB - 170MB Old technology -- slower access

11 Cassette Tape QIC -- Quarter inch cartridge (1/4) –2.5GB to 4GB DAT -- Digital audio tape (4mm) –20GB DDS-3 -- Digital data storage (4mm) –12GB/24GB

12 Cartridge Tape DTF -- Digital tape format (1/2) –42GB DLT -- Digital linear tape (1/2) –35GB/70GB AIT -- Advanced Intelligent (8mm) –25GB VHS -- Video tape SD mm –100GB

13

14 Magnetic Disk Direct access Ability to hold more data in a smaller space Faster data access speeds

15 Floppy Disk 8, 5 1/4, & 3 1/2 I/O device -- floppy disk drive

16 Floppy Disk Capacities DOS 5 1/4 DSDD 5 1/4 DSHD 3 1/2 DSDD 3 1/2 DSHD DSED Floptical SuperDisk 360k 1.2MB 720k 1.44MB 4MB 21MB 120MB

17 Floppy Disk Capacities MAC 3 1/2 DSDD 3 1/2 DSHD Floptical SuperDisk 800k 1.4MB 21MB 120MB

18

19

20 Hard Disk I/O device -- hard disk drive Read/write head

21 Fixed Disk Interfaces –IDE (EIDE) - Integrated Drive Electronics Only daisy chain 2 drives up to 27 GB ULTRA IDE, EIDE –SCSI - Small Computer Systems Interface Daisy up to 6 devices up to 73 GB SCSI-2, SCSI Ultra2/Wide

22

23 Removable Cartridge IOMEGA –ZIP –JAZ –JAZ 2 –Parallel or SCSI SPARQ QUEST –100MB –250MB –1GB –2GB –4.7GB

24 Optical Technology Overview –Large storage capacity –removable –not magnetic Optical Disk –Size –Uses data, video, audio

25 CD-ROM CD-ROM -- Compact Disk, Read-only Memory 650MB CD-R CD-RW 40x

26 DVD DVD -- Digital Videodisk up to 10GB DVD-RAM up to 5.25GB

27 WORM WORM -- Write Once, Read Many 200GB

28 Erasable Drive Magneto-Optical –3.5 MO GB –5.25 MO GB

29 Others Optical Card Optical Tape


Download ppt "GRAP 3175 Computer Applications for Drafting Unit II Computer Hardware."

Similar presentations


Ads by Google