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a history of modern computing 2nd edition phần 4

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63 Đây là những hoạt động tầm thường, nhưng GE cũng hy vọng rằng các máy tính sẽ được nhiều hơn như UNIVAC 1108, là con cháu tự nhiên của IBM 7090. Họ đã được cả hai bán và cho thuê, và giá dao động lên đến $ 250.000. Năm 1967, SDS công bố một máy tính mạnh hơn, | 122 Chapter 4 master file was kept on magnetic tape was retained. Patrick Ruttle of the IRS called this a way of moving into the future in a very safe fashion. 34 Instantaneous on-line access to records was verboten. Hamstrung by a hostile Congress the agency limped along. In 1985 the system collapsed newspapers published lurid stories of returns being left in dumpsters refund checks lost and so on.35 Congress had a change of heart and authorized money to develop a new data-handling architecture. NASA s Manned Space Program Both NASA-Ames and the IRS made attempts to move away from batch processing and sequential access to data and both failed at least at first. But the failures revealed advantages of batch operation that may have been overlooked otherwise. Batch operation preser ved continuity with the social setting of the earlier tabulator age it also had been fine-tuned over the years to give the customer the best utilization of the machine for his or her dollar. The real problem with batch processing was more philosophical than technical or economic. It made the computer the equivalent of a horseless carriage or wireless telegraph it worked faster and handled greater quantities than tabulators or hand calculations but it did not alter the nature of the work. During this period up to the late 1960s direct interactive access to a computer could exist only where cost was not a factor. NASA s Manned Space Program was such an installation where this kind of access was developed using the same kind of hardware as the IRS NASA-Ames and Blue Cross.36 In the late 1950s a project was begun for which cost was not an objection America s race to put men on the Moon by the end of the decade. Most of a space mission consists of coasting in unpowered flight. A lot of computing must be done during the initial minutes of a launch when the engines are burning. If the craft is off-course it must be destroyed to prevent its hitting a populated area. If a launch goes well the .