1956: IBM ships the first hard drive in the RAMAC 305 system. The drive holds 5MB of data at $10,000 a megabyte. The system is as big as two refrigerators and uses 50 24-inch platters.
1973: IBM announces the 3340, the first modern “Winchester” hard drive, which has a sealed assembly, lubricated spindles, and low-mass heads.
1983: Rodime releases the first 3.5-inch hard drive; the RO352 includes two platters and stores 10MB.
Timeline: 50 Years of Hard Drives