A computer system includes an addressing assembly, connected respectively to high bits of a memory address line of a processor and high bits of a word address line of a storage, and used to convert, in a preset continuous or discrete range on the storage, high bits of a memory address formed by the processor into high bits of a corresponding word address of the storage and output the high bits to the storage. Low bits of the memory address line of the processor are connected to low bits of the word address line of the storage. The preset range is smaller than or equal to an addressing range of the memory address line of the processor. The processor changes storage units of the storage covered by the preset range by changing the preset range. Thus it reduces cost, improves operation efficiency, shortens operation time, and has wide applicability.