A FAT (file allocation table) based file system is being used and the total overhead of each entry in the FAT is $$4$$ bytes in size. Given a $$100\,\, \times \,\,{10^6}$$ bytes disk on which the file system is stored and data block size is $${10^3}$$ bytes, the maximum size of a file that can be stored on this disk in units of $${10^6}$$ bytes is __________.

The data blocks of a very large file in the Unix file system are allocated using

Consider a disk pack with 16 surfaces, 128 tracks per surface and 256 sectors per track. 512 bytes of data are stored in a bit serial manner in a sector. The capacity of the disk pack and the number of bits required to specify a particular sector in the disk are respectively:

Normally user programs are prevented from handling $${\rm I}/O$$ directly by $${\rm I}/O$$ instructions in the for $$CPU$$ having explicit $${\rm I}/O$$ instructions, such $${\rm I}/O$$ protection is ensured by having the $${\rm I}/O$$ instructions privilege in $$CPU$$ with memory mapped $${\rm I}/O$$ there is no explicit $${\rm I}/O$$ instruction. Which one of the following is true for a $$CPU$$ with memory mapped $${\rm I}/O$$?