On 14 September 1956  IBM announced the 305 RAMAC. It  was the first commercial computer that used a moving-head hard disk drive (magnetic disk storage) for secondary storage. Test units were already installed at the U.S. Navy and at private corporations. RAMAC stood for “Random Access Method of Accounting and Control”, as its design was motivated by the need for real-time accounting in business.

Orders began pouring in. Early customers included 3M, New York University, Norfolk Naval Shipyard, Pfizer and United Airlines, among others. Within two years, RAMAC had been deployed by the United States Custom House to monitor Atlantic Ocean traffic, reducing the response time to ship distress calls to five minutes. IBM