The hard drive celebrated its birthday on Wednesday, reaching the grand old age of 50.

IBM introduced the first magnetic hard drive in 1956 with the introduction of the IBM 305 Random Access Method of Accounting and Control (Ramac). 

The device signalled the end of punch cards and magnetic drums as the primary storage mediums.

IBM's Ramac offered 5MB of storage on a total of 50 disks measuring 24in in diameter.

The disks were stacked on a cylinder and a reader head moved from one disk to the other to retrieve information. It was considered too expensive to have 50 reader heads.

Ramac was housed in an enclosure about the size of two fridges, and weighed several tons.

Disk storage capacities have since increased by a factor of 70,000, while the disks have shrunk to sizes as small as 1in.

Back in 1956 IBM only leased its computer equipment, as the Ramac had a price tag of about $50,000. Adjusted for inflation, it would cost about $360,000 today.

• Photos of the Ramac are available on the Silicon Valley Sleuth blog