What Was the First Hard Disk Drive?
The engineers at IBM’s San Jose California laboratory invented the hard disk drive as early as 1953, but its first commercial use wasn’t until 1956.
An IBM press release from September 14, 1956 marks the first official announcement of the 350 disk storage. Several “test RAMAC’s” were shipped in 1956 other RAMAC’s were shipped mid-1957.
The 305 RAMAC, which housed the 350 disk storage, was released alongside another very similar model the 650 RAMAC, which came with 355 disk storage. The 355 disk storage was also invented in 1953, announced in 1956, and shipped in 1957.
This is the original promotional video for the 305 RAMAC.
305 RAMAC and 350 Disk Storage Specs
The 350 disk storage itself had 50 24-inch disks contained inside a cabinet and could store 5 MB of data. The 350 RAMAC’s “random access” arm could retrieve data stored on any of 50 spinning disks in less than a second.
A working model can be seen in this video.
The original 305 RAMAC or “Random Access Method of Accounting and Control” (as its design was motivated by the need for real-time accounting in business) could be housed in a room of about 9 m (30 ft.) by 15 m (50 ft.); the 350 disk storage unit measured around 1.5 square meters (16 sq ft.).
Assembled with covers, the 305 RAMAC was 60 inches long, 68 inches high and 29 inches deep.