Disk Velocity
Bit near centre of rotating disk passes fixed point slower than bit on outside of disk
• Increase spacing between bits in different tracks
• Rotate disk at constant angular velocity (CAV)
—Gives pie shaped sectors and concentric tracks
—Individual tracks and sectors addressable
—Move head to given track and wait for given sector
—Waste of space on outer tracks
– Lower data density
• Can use zones to increase capacity
—Multiple zone recording
—Each zone has fixed bits per track
—More complex circularity