Prior to IBM introducing the first computer with a hard disk in 1956 [CED01], computers used core memory, tape, and drums for data storage.
The 3040 Winchester was named after the Winchester 30-30 rifle because of its storage capacity and access time of 30Mb and 30 milliseconds.
Today’s disk platters are normally composed of two materials: the first giving the platter its strength and the second being magnetic coating.
The unformatted capacity of a disk disregards low-level components such as preamble, ECC (Error Correction Code), and intersector gaps used to electromechanically control the R/W heads.
Today’s disk speeds are measured in revolutions per minute (RPMs) and include 5,400, 7,200, 10,000, and 15,000 RPM disks.
The disk-access method ...