The first hard disk drive for personal computers, introduced in 1979 by Seagate. It transferred data at 625 KBytes/sec, using the MFM encoding method. Today's drives hold 400,000 times more data with transfer rates a thousand times faster. See ST412 and hard disk.
Seagate's ST506 was the first hard disk drive for personal computers. This 5.25" full-height drive held 5MB and became the standard for CP/M machines and, later, the IBM PC and its successors. (Image courtesy of Seagate Technology, Inc.)