`DiskDrive`

Class:	Disk
Name:	DiskDrive
Comment:	Simulates a physical disk drive and follows these steps DiskScheduler makes a read/write request if the disk can't satisfy this request then CPU.generateInterrupt( disk_access_error, NOW ) else compute how long it will take to perform request CPU.generateInterrupt( type_of_transfer_complete, TIME ) Should possibly add the presence of a disk buffer provided by the disk along the lines of Nachos' track buffer
Collaborators:	DiskTransfer - contain information about whether the transfer is a read or write and to where Interrupt - raised after disk has computed how long it will take to finish the request DiskType - parameters about disk

DiskDrive( DiskType theDiskType ) - initialise disk with various parameters
DiskRequest( DiskTransfer theTransfer ) - receive the type of transfer to perform
int time = ComputeTime( DiskTransfer theTransfer ) - calculate how long to satisfy request

DiskDrive