Presentation Transcript

1. CIS 101: Introduction to Computers Chapter7Storage Hard Disks Memory Cards Levi Krein Associate Professor CIS
2. What isstorage? Holds data, instructions, and information for future use Storage mediumis physical material used for storage Also called secondary storage Levi Krein Associate Professor CIS p. 7.02 Fig. 7-1
3. Kilobyte (KB) 1 thousand Megabyte (MB) 1 million 1 billion Gigabyte (GB) Terabyte (TB) 1 trillion Petabyte (PB) 1 quadrillion Exabyte (EB) 1 quintillion Zettabyte (ZB) 1 sextillion Yottabyte (YB) 1 septillion What iscapacity? Number of bytes (characters) a storage medium can hold Largest single database is 500 Terabytes at an east coast university (nuclear accelerator data) Levi Krein Associate Professor CIS
4. How does volatility compare? Storage medium is nonvolatile—contents retained when power is off Memory is volatile—holds data and instructions temporarily Levi Krein Associate Professor CIS
5. Functions as source of Input Records Output What is astorage device? Hardware = I/O or Read/Write Devices Memory SDRAM Reading Process of transferring items from storage media to memory Writing Process of transferring items from memory to storage media Levi Krein Associate Professor CIS
6. Stores … Primary Storage Memory (most RAM) Items waiting to be interpretedand executed by the processor Secondary Storage Hard Disk Operating system, applicationsoftware, user data and information Flash Memory Cards and USB Flash Drives Digital pictures or files to be transported CDs and DVDs Software, backups, movies, music Tape Backups Access time is the combination of two tasks: Time it takes storage device to locate item on storage medium Time required to deliver item from memory to processor Remember, the access time of RAM is 200,000 times faster than a hard drive fastertransferrates Data Transfer Rate slowertransferrates Levi Krein Associate Professor CIS
7. Link to “How Hard Disks Work” hard disk installedin system unit What is ahard disk? High-capacity storage Consists of several inflexible, circular platters that store items magnetically Components enclosed in airtight, sealed case for protection High-speed platters spin at 5400-7200 rpm Hard Drive = 7200 rpm 120 rpSecond Levi Krein Associate Professor CIS
8. Magnetic Disks Trackis narrow recording bandthat forms fullcircle on disk Sectorstores up to512 bytesof data Formatting prepares disk for use
9. How does disk storage work? Disks areMagnetic = data is stored by aligning positive & negative particles Levi Krein Associate Professor CIS
10. Magnetic Disks Sample Hard Disk Characteristics Advertised capacity 120 GB Platters 3 Read/write heads 6 Cylinders 16,383 Bytes per second 512 Sectors per track 63 Sectors per drive 234,441,648 Revolutions per minute 7,200 Transfer rate 133 MB per second Access time 8.9 ms What are characteristics of a hard disk? actualdiskcapacity Check the capacity of our lab computers 750 GB Fall 2006 Levi Krein Associate Professor CIS p. 361 Fig. 7-11
11. How does a hard drive look? Platters are made of metal (aluminum), glass, or ceramic & has a metal surface that can be magnetized. Levi Krein Associate Professor CIS
12. Video: Install a New Hard Drive Sale Obsolete Speed up your computer with a new hard drive Hard Drive Video $60 $65 $60 Sept. 2009 $90 New 1 Terabyte Levi Krein Associate Professor CIS
13. platter What is acylinder? track Vertical section of track through all platters Same track number on multiple surfaces sector Single movement of read/write head arms accesses all platters in cylinder; reduce access time read/writehead platter sides Levi Krein Associate Professor CIS cylinder
14. Maintaining Hard Disk Data A little Preventive maintenance! Defragment = reorganize files to make better used of space; programs will run faster Two ways: 1 – Start, Accessories, System Tools 2 – My Computer, Properties, Disk Cleanup & Tools Levi Krein Associate Professor CIS
15. What is ahead crash? Occurs when read/write head touchesplatter surface Spinning creates cushion of air that floats read/write head above platter Clearance between head and platter is approximately two-millionths of an inch A smoke particle, dust particle, or human hair could render drive unusable hair read/write head dust clearance smoke platter Levi Krein Associate Professor CIS
16. processor disk cache first requestfor data—to disk cache second requestfor data—to hard disk hard disk What is adisk cache? Portion of memory that processor uses to store frequentlyaccessed items Levi Krein Associate Professor CIS
17. What areexternal hard disksandremovable hard disks? Used to back up or transfer files External hard disk — freestandinghard disk that connects to system unit Removable hard disk — hard diskthat you insert and removefrom hard disk drive Hard drive is designated as drive C Levi Krein Associate Professor CIS
18. What is a miniature hard disk? Provide greater storage capacities than flash memory Smaller than notebook computer hard disks A pocket hard drive is a self-contained unit Levi Krein Associate Professor CIS
19. Magnetic Disks – What is a disk controller? SATA(Serial Advanced Technology Attachment) controller uses serial signals to transfer data, instructions, and information EIDE (EnhancedIntegratedDrive Electronics) controller supports four hard disks, provides connections for CD and DVD drives SCSIcontroller supports up to fifteendevices including hard disks, CDand DVD drives, tape drives, printers, scanners, network cards SAScontroller supports many connecteddevices at once, including hard disks,CD and DVD drives, printers,scanners, digital cameras, and more Chip and circuits that control transfer of data from disk
20. What is online storage? Service on Web that provides storagefor minimal monthly fee Files can be accessed from any computer with Web access Large files can be downloaded instantaneously Others can be authorized to access your data Offsite backup of data Video Levi Krein Associate Professor CIS
21. Magnetic Disks – What is a floppy disk? Portable, inexpensive storage medium (also called diskette) Obsolete? Thin, circular, flexible film enclosedin 3.5” wide plastic shell
22. Optical Discs = CDsand DVDs Push the button toslide out the tray. Flat, round, portable metal discs with protective plastic coating Can be read only or read/write Insert the disc,label side up. Most PCs include an optical disc drive Push the same buttonto close the tray. Disc: Alternative spelling of disk. Disc is often used for optical discs, while disk generally refers to magnetic discs, but there is no real rule. Levi Krein Associate Professor CIS
23. disc label lens lens pit land Step 3.Reflected light is deflected to alight-sensing diode, which sends digital signals of 1 to computer. Absence of reflected light is read as digital signal of 0. 0 1 prism prism light-sensingdiode light-sensingdiode laserdiode laserdiode How does a laser read data on a CD or DVD? Link to “How CDs Work” Pit Land Step 2.If light strikesa pit, it scatters. If light strikes a land, it is reflected back toward diode. Step 1.Laser diode shines a light beam towarddisc. Levi Krein Associate Professor CIS
24. How is data stored on a CD or DVD? Typically stored in singletrack Track divided into evenly sizedsectorsthat store items single trackspirals to edgeof disc disc sectors Levi Krein Associate Professor CIS
25. What is aCD-ROM? Compactdiscread-onlymemory Cannot erase or modifycontents Single-session Typically holds 650 MB to 1 GB Commonly usedto distributemultimedia (music) and complexsoftware Levi Krein Associate Professor CIS
26. What is the data transfer rate of a CD-ROM drive? Original CDs Transferred at 150 KBps (kilo bytes per second) 1X 10X = 150 x 10 or 1,500 KBps 1X 10X 48X 75X ? 48X: 48  150 KBps = 7,200 KBps or 7.2 MBps 75  150 KBps = 11,250 KBps or 12.25 MBps Levi Krein Associate Professor CIS
27. Stores digital versions of roll of film Film developers offer Picture CD service Can be modified using photo editing software Kodak What is aPicture CD? Step 1.Drop off film to be developed. Mark the Picture CD box on the film-processing envelope. Step 3.At home, print images from Picture CD on your ink-jet photo printer. Step 2.When you pick up prints and negatives, a Picture CD contains digital images of each photograph. At a store, print images to Picture CD at kiosk. A CD-ROM drive can read a Picture CD & other CDs (but CAN NOT read DVDs) Levi Krein Associate Professor CIS p. 7.19 Fig. 7-25
28. Multi-session? What areCD-Rs and CD-RWs? Must haveCD recorderor CD-R drive CD-R (compact disc-recordable) —c disc you can write on once Cannot erasedisc’s contents CD-RW (compact disc-rewritable) — ceerasabledisc you can write onmultiple times Must haveCD-RW softwareand CD-RW drive DVD-R DVD-RW Levi Krein Associate Professor CIS
29. What is aDVD-ROM ? digital versatile disc -ROMor digital video disc -ROM? High capacity disc capable of storing 4.7 GB to 17 GB Must haveDVD-ROM driveor DVD player to read DVD-ROM Stores databases, music, complex software, and movies DVD DVD drive Levi Krein Associate Professor CIS
30. DVDs Blu-ray discsstorage capacity = 100 GB Blu-ray has won the high definition storage medium for movies HD-DVD discs lost out to Blue-ray HD-VMDs have storage capacity of up to 40 GB or more Competitor to Blu-ray 20 layers UMDcan store up to 1.8 GB Mini-DVD; PlayStation Portable Levi Krein Associate Professor CIS
31. DVD-ROM Storage Capacities Sides Layers Storage Capacity 1 1 47 GB 1 1 8.5 GB 2 1 9.4 GB 2 2 17 GB How does a DVD-ROM store data? Two layers of pits are used, lower layer is semitransparent so laser can read through Some are double-sided Data is packed (pits are closer together) more densely DVD-RWis a rewritable DVD It can write on CD-R, CD-RW, DVD-R & DVD-RW Levi Krein Associate Professor CIS
32. What istape? Magnetically coated plastic ribboncapable of storing large amountsof data at low cost Sequential access, like music Primarily used for backup Sequential access is the opposite of Direct access — used on hard disks, CDs, and DVDs — which can locate particular item immediately Levi Krein Associate Professor CIS p. 7.24 Fig. 7-29
33. What is aPC Card? Adds capabilities to computer Credit-card-sized device commonlyused in notebook computers Levi Krein Associate Professor CIS
34. CompactFlash Secure Digital xD Picture Card Memory Stick What isminiature mobile storage media? Storage for small mobile devices Miniaturemobile storagemedia Levi Krein Associate Professor CIS
35. What is acard reader? Reads information stored on miniature mobile storage media Type of card determines type of card reader needed Levi Krein Associate Professor CIS
36. What is aUSB Flash Drive? Plugs in a USB port on a computer or mobile device Storage capacities up to 64 GB Video How flash drives are made. Check out the robotics. 8 minutes Levi Krein Associate Professor CIS
37. What is asmart card? Stores data on microprocessor embedded in small card Input, process, output, and storage capabilities Sometimes calledintelligentsmart card Prepaid telephone cards Levi Krein Associate Professor CIS
38. Microfilm — 100- to215-foot roll of film Microfiche — small sheet of film, usually 4”  6” What aremicrofilmandmicrofiche? Store microscopic imagesof documents on roll or sheet of film Levi Krein Associate Professor CIS
39. How do life expectancies of various media compare? Microfilm and microfiche have longest life of any storage media Levi Krein Associate Professor CIS
40. Drive Letter Designations Levi Krein Associate Professor CIS Floppy Disks Drive Letter A & B Hard Disks Drive Letter C More Hard Disks = D, E, etc. Optical Drives Next available letter after hard disks Flash Drives Next available letter after optical drives
41. Other Storage Devices View Video Levi Krein Associate Professor CIS Dogtags
42. Other Storage Devices Storage Cube View Video Notice Floppy Disks and Magnetic Tape Levi Krein Associate Professor CIS
43. Summary of Storage Chapter 7 Completed Levi Krein Associate Professor CIS