A 5-megabyte hard drive loaded onto a plane in 1956. The system, called a 305 RAMAC, cost $3,200 per month to lease. The Volume and Size of 5MB memory storage in 1956. In September 1956 IBM launched the 305 RAMAC, the first computer with a hard disk drive (HDD). The HDD weighed over a ton and stored 5MB of data.