secondary storage

[′sek·ən‚der·ē ′stȯr·ij] (computer science) Any means of storing and retrieving data external to the main computer itself but accessible to the program.

secondary storage

(storage)Any non-volatile storage medium that is notdirectly accessible to the processor. Memory directlyaccessible to the processor includes main memory, cacheand the CPU registers. Secondary storage includes hard drives, magnetic tape, CD-ROM, DVD drives, floppy disks, punch cards and paper tape.

Secondary storage devices are usually accessed via some kindof controller. This contains registers that can be directlyaccessed by the CPU like main memory ("memory mapped").Reading and writing these registers can cause the device toperform actions like reading a block of data off a disk orrewinding a tape. See also DMA.

Programs and data stored in secondary storage must first beloaded into main memory before the processor can use them.

secondary storage

secondary storage