hard disk operating system assignment group 183 bunga burhan danny arinal prio copyright c 2006 2 12 10 06 overview description history major parts of data structures in drives drive specifications scheduling performance 3 definition a is digitally encoded non volatile storage device which stores on rapidly rotating disks with magnetic surfaces platters computer memory that can retain the stored information even when not powered 4 before early 1980s most had 8 inch 20 cm or 14 35 required an equipment rack large amount floor space after 1980 seagate technology introduced st 506 first 5 25 capacity megabytes st4053 40 mbyte 1 full height clunker st506 interface and voice coil circa 1987 http en wikipedia org wiki also phillips optical laser 1981
