======================COMPONENTS_MEMORY===================================== AUDIO CASSETTE standard recording speed = 1 7/8 inches per second Recoding time = 30 minutes per side, tape length = 3,375 inches = 281 feet, 4 tracks 15KHz upper frequency limit, 16bits conversion at 35KHz sample rate = 560Kbs/sec 560Kbs/sec x 4 tracks x 1800 seconds = 4,032Mb or 504MBs total storage. Tape width = 0.125" Total recordable area = 422 square inches Bit density = 504MBs/422 square inches = 1.2MBs/ square inch, 186KBs/ sq cm Bit size = 300 micro inches = 8.2 micro meters 1.44M FLOPPY DISKS Double sided, Outer track radius = 1.65" Inner track radius = 0.8" Recordable area each side = 6.54 square inches or 42.2 square cm At 720KBs per side, storage density = 110KBs per sq inch or 17KBs per square cm Bit size = 1065 micro inches = 27 micro meters 120MB "Super Disk" FLOPPY DISKS Double sided, so 60MBs per side Same 6.54 square inch (42.2 sq cm) recording area as standard floppy Storage density = 9.17MBs per square inch, 1.42MBs per sq cm Bit size = 117 micro inches = 2.97 micro meters HIGH DENSITY HARD DISKS Reported bit density = 1GB/ sq inch = 8Gb/ sq inch Bit size = 11 micro inches = 0.28 micro meters CD-ROM DISKS Single sided. 4.70" diameter outer track radius = 2.30" Inner track radius 0.90" Recordable area = 14 square inches or 90.3 square cm 650MBs total storage on one side Storage density = 46MBs per square inch or 7.2MBs per square cm. Bit size = 52 micro inches = 1.3 micro meters QCD-R drive discs greenish or bluish on one side? Along track are flat reflective areas and non-reflective bumps. flat reflective area represents a binary 1, while a non-reflective bump represents a binary 0. A CD-R disk therefore has an extra layer that laser can modify. This extra layer is a greenish dye. CD-R you have a plastic substrate, a dye layer and a reflective gold layer. On new CD-R disk entire surface of disk is reflective -laser can shine through dye and reflect off gold layer. writing laser ( much more powerful than reading laser) heats up dye layer and changes its transparency. manent change and both CD and CD-R drives can read the modified dye as a bump later on. It turns out that the dye is fairly sensitive to light in order for a laser to modify it very quickly. Therefore avoid exposing CD-R disks to sunlight. 4.6GBs DVD OPTICAL DISKS Recording area = 14 square inches or 90.3 square cm (same as CD-ROM) 4.6GBs total storage per side. Storage density = 329MBs per square inch or 51MBs per square cm Bit size = 19.5 micro inches = 0.49 micro meters FUTURE OPTICAL DISKS USING 220nM ULTRAVIOLET LASER LIGHT Recording area = 14 square inches or 90.3 square cm (same as CD-ROM) Assuming 8 times the storage due to the shorter light wave length Storage capacity = 36GBs per side MP3 files CD stores music using 44,100 samples per second, 16 bits per sample and two channels 10 million bytes of data per minute of music three minute song requires 30 megabytes of data. MPEG acronym for Moving Picture Experts Group. developed compression systems used DVD movies, HDTV broadcasts and DSS satellite systems use MPEG compression includes a subsystem to compress sound, called MPEG audio Layer-3. abreviation - MP3. MP3 compress a song by a factor of 10 or 12 retain CD Non-Volatile Memory data is retained even if the circuit is powered down EPROM Erasable Programmable Read-Only Memory : Requires 12-volt power supply for programming. Whole chip is erased via exposure to UV 1 ight. EEPROM Electrically Erasable Programmable Read-Only Memory: Requires no extra power supply other than Vcc. Provides both electrical program and erase functionality together with capability to alter single byte at a time. Larger cell size than EPROM. FLASH A hybrid between EPROM and EEPROM. Offers the electrical re-programability of EEPROM with a cell size approaching that of an EPROM. Byte-by-byte erase is not available erased ' large sectors, in whole-chip ("Flash") erase. EEPROM TECHNOLOGIES typically require on-chip voltages of 15-19 volts during program mode,so high-voltage transistors must be provided, AUDIO CASSETTE TAPES standard recording speed 1 7/8 inches per second 30 minutes per side, tape length = = 281 feet, 4 tracks 15KHz upper frequency limit 16bits conversion 35KHz sample rate = 560Kbs/sec 560Kbs/sec x 4 tracks x 1800 seconds 4,032Mb or 504MBs total storage. Tape width = 0.125" Total recordable area = 422 square inches Bit density = 504MBs/422 square inches 1.2MBs/ square inch, 186KBs/ sq cm Bit size = 300 micro inches = 8.2 micro meters 3 1/2" 1.44M FLOPPY DISKS Double sided, Outer track radius = 1.65" Inner track radius = 0.8" Recordable area each side = 42.2 square cm At 720KBs per side, storage density 17KBs per square cm Bit size = = 27 micro meters NEW 120MB "Super Disk" FLOPPY DISKS Double sided, so 60MBs per side Same42.2 sq cm) recording area as standard floppy Storage density 1.42MBs per sq cm Bit size = = 2.97 micro meters HARD DISKS Reported bit density = 1GB/ sq inch = 8Gb/ sq inch Bit size = 11 micro inches = 0.28 micro meters CD-ROM DISKS Single sided. 4.70" diameter outer track radius = 2.30" Inner track radius 0.90" Recordable area = 90.3 square cm 50MBs total storage on one side Storage density = 7.2MBs per square cm. Bit size = 52 micro inches = 1.3 micro meters 4.6GBs DVD OPTICAL DISKS Recording area = 90.3 square cm (same as CD-ROM) 4.6GBs total storage per side. Storage density = 51MBs per square cm Bit size = 0.49 micro meters FUTURE OPTICAL DISKS USING 220nM ULTRAVIOLET LASER LIGHT Recording area = 90.3 square cm (same as CD-ROM) Storage capacity = 36GBs per side Bit size = 7 micro inches = 0.18 micro meters