Operating System Fundamentals
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best answers from c, Lesson 2 C# Windows Forms
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- Figure 5.6 Inside a Hard Disk
| Track Sector Floppy Disk Platter Figure 5.5 Tracks and Sectors on a Floppy Disk In addition to creating tracks and sectors, when you format a floppy disk, you also create a boot record, a File Allocation Table (FAT) and a Root Directory. The boot record is always the first sector on a disk. It contains a bootstrap loader, which can be used to boot a computer from the disk, as well as information about how the disk is organized. The File Allocation Table lists the location of all clusters on the disk, and how they are currently being used. The Root Directory lists all of the files and subdirectories currently stored on the disk. Hard disks are somewhat different from floppy disks. A hard disk contains several physical platters which are stacked on top of each other. Each platter is double-sided, with tracks and sectors drawn on the surface. All of the concentric tracks that lineup with each other on each platter are referred to as a cylinder. Figure 5.6 (below) shows how the platters stack up inside of a hard disk. There is a read/write arm (with a read/write head) for each platter surface. Operating System Fundamentals 72 Figure 5.6 Inside a Hard Disk Another difference between the physical structure of a floppy disk and a hard disk is the size of the sectors and clusters on the disk. Cluster size varies on hard disks, depending upon the actual size of the disk, the file system used, and the number of partitions. On a floppy disk, the sector size is fixed at 512 bytes. That means, the closer you get to the center of the physical disk, the fewer the number of sectors per track. On newer hard disks, the sectors get smaller as you get closer to the center of the disk. This means that you can have the same number of sectors for each track. The differences in how tracks are divided into sectors on floppy disks and hard disks are shown in Figure 5.7 (below. Download 2.34 Mb. Share with your friends:
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