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Chapter 7.1: The Operational Environment: A Short History
           data. Over time, the oxide was stripped off of the magnetic tape files, thus rendering the
           file unusable.


           With disk storage, data could be accessed directly. This meant that there was no longer a
           need to access an entire file in order to get to one record.


           Fig. 7.1.5 shows the symbol for a disk storage device.









































               Fig. 7.1.5 Disk storage.


           The first iterations of disk storage were expensive and fragile. But over time, the
           capacity, cost, and stability of the disk files improved.


           And soon, applications were using disk storage, not magnetic tape files.


           Fig. 7.1.6 shows that applications were built where data could be accessed on disk
           storage.








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