听力原文：On September 13,1956, IBM shipped the first unit of the RAMAC, in other words, Random Access Method of Accounting and Control. The RAMAC, designed in Big Blue's San Jose, Calif., research center would have made a lousy music player. The drive weighed a full ton, and to lease it you'd pay about ＄250,000 a year in today's dollars. Since it required a separate air compressor to protect the two moving 'heads' that read and wrote information, it was noisy. The total amount of information stored in its 50 spinning iron-oxide-coated disks-- each of them a pizza-size 24 inches -- was 5 megabytes. Which of the following is true according to the passage?