Classnotes

Computer Systems

eXercise #7

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Secondary Storage

1. Regarding DOS Disk storage generally:
   1. Differentiate between a SECTOR and a CLUSTER
   2. List the components of a DIRECTORY ENTRY
   3. Describe the processes that LIMIT the rate of data transfer to/from a disk
   4. Drescribe how a QUICK FORMAT differs from a complete format
   5. How are we able to UNDELETE files immediately after we have DELETED them?
   
   
2. Regarding FLOPPY DISKS
   1. What does FORMATTING the disk do to it?
   2. How can the machine detect whether the disk is BOOTABLE or not
   3. Suppose you are saving many SMALL (1-2Kb) files onto a floppy. Under what conditions would the system report DISK FULL when there was still unused storage space
   
   
3. Under Apple DOS 3.1, a 5.25" Floppy disk is formatted single sided with 35 tracks, 16 segments. If each segment contains 256 bytes on an Apple system then calculate the capacity of the disk
   
   
4. Suppose a hard disk drive (HDD) is registered in CMOS with the following characteristics: 619 Cylinders, 64 heads, 63 sectors.
   1. If each of the sectors can hold 512 bytes, calculate the capacity of the HDD in Gigabytes
   2. How many double-sided high density 3.5" floppy disks would it take to BACK UP this HDD assuming it is possible without storage space wastage on the floppys, and ZIPPING was NOT USED?
   3. IF the HDD was ONE partition, what size would the CLUSTERS be?
   4. Indicate the size of the PARTITIONS if you wanted to ensure that no cluster exceeded 8Kb
   
   
5. Regarding Hard Disks Generally:
   1. What is DEFRAGGING, and why is it important for the 'efficient' retrieval of information from a HDD?
   2. Explain how an UNDELETE is possible
   3. How does a QUICK FORMAT differ from a FULL FORMAT?
   
   

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Solutions