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2. Introduo 3. Tipos de Memria Externa
6. CD-R/W 7. DVD
8. Disco Magntico
9. Substrate used to be aluminium 10. Now glass
12. Better shock/damage resistance 13. Disco Magntico 14. Disco Magntico 15. Vdeo sobre funcionamento do disco rgido 16. Vdeo sobre disco rgido de vidro 17. Histria
18. Em 1973 a IBM lanou o modelo 3340 Winchester, com dois pratos de 30 megabytes e tempo de acesso de 30 milissegundos. Assim criou-se o termo 30/30 Winchester (uma referncia espingarda Winchester 30/30), termo muito usado antigamente para designar HDs de qualquer espcie. 19. Ainda no incio da dcada de 1980, os discos rgidos eram muito caros e modelos de 10 megabytes custavam quase 2 mildlares americanos, 20. Usos
21. J para celular os primeiros a terem esse tecnologia foram os da Nokia e da Samsung.[2] E tambm devemos lembrar que atualmente o disco rigido no s interno, existem tambm os externos. 22. Leitura e gravao
23. Read and Write Mechanisms
24. May be single read/write head or separate ones 25. During read/write, head is stationary, platter rotates 26. Write
28. Magnetic pattern recorded on surface below
31. Electrical resistance depends on direction of magnetic field 32. High frequency operation
33. Cabea magntica tradicional
Gravao
Leitura
34. Cabea magntica tradicional 35. Inductive Write MR Read (moderno) 36. Organizao de dados e formatao
37. Espaos entre as trilhas
39. Constant angular velocity
40. Minimum block size is one sector 41. May have more than one sector per block 42. Organizao dos dados no disco 43. Controle 44. Formatao 45. Formatao 46. Caractersticas fsicas 47. Cabeotes fixo e mvel 48. Discos simples ou mltiplos 49. Whinchester
50. Disk Velocity
51. Increase spacing between bits in different tracks 52. Rotate disk at constant angular velocity (CAV)
54. Move head to given track and wait for given sector 55. Waste of space on outer tracks
57. Disk Layout Methods Diagram 58. Finding Sectors
59. Format disk
61. ST506 format (old!)
Gap1 Id Gap2 Data Gap3 Gap1 Id Gap2 Data Gap3 Track Sync Byte Head Sector CRC Sync Byte Data CRC 62. Characteristics
63. Removable or fixed 64. Single or double (usually) sided 65. Single or multiple platter 66. Head mechanism
68. Flying (Winchester) 69. Fixed/Movable Head Disk
72. Removable or Not
74. Easy data transfer between systems
75. Multiple Platter
76. Heads are joined and aligned 77. Aligned tracks on each platter form cylinders 78. Data is striped by cylinder
80. Multiple Platters 81. Cylinders 82. Floppy Disk
83. Small capacity
84. Universal 85. Cheap 86. Obsolete? 87. Winchester Hard Disk (1)
88. Sealed unit 89. One or more platters (disks) 90. Heads fly on boundary layer of air as disk spins 91. Very small head to disk gap 92. Getting more robust 93. Winchester Hard Disk (2)
94. Cheap 95. Fastest external storage 96. Getting larger all the time
97. Removable Hard Disk
99. Only 100M
102. Speed
103. Transfer rate 104. Timing of Disk I/O Transfer 105. Optical Storage CD-ROM
106. 650Mbytes giving over 70 minutes audio 107. Polycarbonate coated with highly reflective coat, usually aluminium 108. Data stored as pits 109. Read by reflecting laser 110. Constant packing density 111. Constant linear velocity 112. CD Operation 113. CD-ROM Drive Speeds
115. Track (spiral) is 5.27km long 116. Gives 4391 seconds = 73.2 minutes
117. e.g. 24x 118. Quoted figure is maximum drive can achieve 119. CD-ROM Format
120. Mode 1=2048 byte data+error correction 121. Mode 2=2336 byte data 122. Random Access onCD-ROM
123. Move head to rough position 124. Set correct speed 125. Read address 126. Adjust to required location 127. (Yawn!) 128. CD-ROM for & against
129. Easy to mass produce 130. Removable 131. Robust
132. Slow 133. Read only 134. Other Optical Storage
136. Compatible with CD-ROM drives
138. Mostly CD-ROM drive compatible 139. Phase change
140. DVD - whats in a name?
141. Officially - nothing!!! 142. DVD - technology
143. Very high capacity (4.7G per layer) 144. Full length movie on single disk
145. Movies carry regional coding 146. Players only play correct region films 147. Can be fixed 148. DVD Writable
149. First generation DVD drives may not read first generation DVD-W disks 150. First generation DVD drives may not read CD-RW disks 151. Wait for it to settle down before buying! 152. CD and DVD 153. Magnetic Tape
154. Slow 155. Very cheap 156. Backup and archive 157. Digital Audio Tape (DAT)
158. High capacity on small tape
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