{HEAD ~ The docking bay} replaces either a hard disk drive or {TAIL ~ a floppy disk drive} in the personal computer 
replaces
{ HEAD ~ The docking bay } replaces either a hard disk drive or { TAIL ~ a floppy disk drive } in the personal computer
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH