Hard Disk Platter

A round magnetic plate that constitutes part of a hard disk.

In 1956, The era of magnetic disk storage dawned with IBM's 305 RAMAC. The 305 is the first magnetic hard disk for data storage, and the RAMAC (Random Access Method of Accounting and Control) technology soon becomes the industry standard. The storage capacity of the 305's 50 two-foot diameter disks was 5 megabytes of data. The platters, stacked one on top of the other, rotated with a common drive shaft.

14 inch. platter

Hard magnetic disks platters come in a variety of sizes, as shown by these three individual disks. Disk packs can vary in the number of disks they contain.

Hard disks platters are contained within the round disk pack shown on top of the cabinets, which contain the disk drives. When it was to be used, a disk pack was lowered into the open compartment.