March 2018
Beginner
744 pages
26h 5m
English
This chapter has given you a broad overview of many aspects of computer input/output and storage systems. You have learned that different classes of machines require different I/O architectures. Large systems store and access data in ways that are fundamentally different from the methods used by smaller computers. For the very smallest computers—such as embedded processors—programmed I/O is most suitable. It is flexible, but it doesn’t offer good performance in general-purpose systems. For single-user systems, interrupt-driven I/O is the best choice, particularly when multitasking is involved. Single-user and medium-sized systems usually employ DMA I/O, in which the CPU offloads I/O to the DMA circuits. Channel I/O is best ...