MASTER OF COMPUTER APPLICATIONS
Course Code : MCS-012
Course Title : Computer Organisation and Assembly Language Programming
Assignment Number : MCA(I)/012/Assignment/15-16
Maximum Marks : 100
Weightage : 25%
Explain the term FAT in the context of disk operating system. What will be the size of a disk and it’s FAT, if a disk has 64 tracks with each track having 16 sectors and size of each sector is 512 byte? You may take the cluster size as 4 sectors.
Given:
Disk has 64 tracks
Track has 16 sectors
Sector is 512 byte (0.5 KB)
Cluster size as 4 sectors
Find:
Disk Size (or Disk Capacity)?
It’s FAT (or FAT entries)?
Track Size (in KB) = No. of Sector x No. of Btyes
= 16 * 0.5 KB
= 8 KB
Cluster Size (in KB) = No. of Track x No. of Sector
= 64 * 8 KB
= 512 KB
Disk Size (in KB) = No. of Cluster x No. of Track
= 4 * 512 KB
= 2048 KB
=2MB
Disk Size (or Disk Capacity) = 2 MB
Note: FAT contains vital information; two copies of FAT are stored on the disk, so that in case one gets destroyed, the other can be used
It’s FAT (or FAT entries) = Disk Size (or Disk Capacity) / Cluster Size
= (2 * 1024 * 1024) / (2 * 1024)
= (2 * 1024 * 1024) / (2 * 1024)
= 1024 No. of entries
Note: FAT contains vital information; two copies of FAT are stored on the disk, so that in case one gets destroyed, the other can be used (Acutual entries = 1024 entries / 2 = 512 entries).