Computer System, Computer Science, Hardware.
usually takes less than 1 ms. 读写头定位到扇区后，驱动器读写内容的时间，依赖转速和每个磁道的扇区数。亚ms级。 Accessing Disks The CPU issues commands to I/O devices using a technique called memory-mapped I/O (Figure 6.12(a)). In a system with memory-mapped I/O, a block of addresses in the address space is reserved for communicating with