Input Output Management
Device drivers are software programs that allow a computer's operating system to communicate with hardware devices, such as printers, graphics cards, and network adapters. They act as a bridge between the hardware and the software, ensuring that the devices function correctly.
Device controllers are hardware components that manage the communication between the CPU and peripheral devices. They handle the incoming and outgoing signals, converting data from the device into a format that the CPU can understand.
Interrupts are signals sent to the CPU by hardware or software indicating that an event needs immediate attention. When an interrupt is received, the CPU pauses its current tasks, saves its state, and executes an interrupt handler to address the event.
Direct Memory Access (DMA) is a feature that allows certain hardware subsystems to access the main system memory independently of the CPU. This enables faster data transfers and frees up the CPU to perform other tasks.
Polling is a method where the CPU repeatedly checks the status of a peripheral device to see if it needs attention. This can be inefficient as it consumes CPU resources, but it is simple to implement.
Spooling (Simultaneous Peripheral Operations On-line) is a process where data is temporarily stored to be processed later. For example, print spooling involves storing print jobs in a buffer before they are sent to the printer.
Disk structure refers to the organization of data on a disk. It includes the physical layout of the disk, the file system used to manage files, and the methods for accessing and storing data.
Disk scheduling algorithms are used to determine the order in which disk I/O requests are processed. Common algorithms include First-Come-First-Served (FCFS), Shortest Seek Time First (SSTF), and Elevator (SCAN) scheduling.