IOManagement

What is Direct Memory Access (DMA)?

Direct Memory Access (DMA) is a hardware mechanism that lets a peripheral device transfer data directly to or from main memory without routing every byte throu…

Polling vs Interrupt-Driven I/O: What Is the Difference?

Polling is where the CPU repeatedly checks a device’s status register in a loop until it is ready, while interrupt-driven I/O lets the CPU do other work and re…

What is Spooling in Operating Systems?

Spooling (Simultaneous Peripheral Operations On-Line) is a technique where output or input data for a slow device is first buffered onto a faster intermediate…

What is a Device Driver and Why Does an OS Need One?

A device driver is a piece of kernel (or kernel-adjacent) software that translates the operating system’s generic I/O requests into the specific commands a par…

What is I/O Buffering and Why Is It Needed?

I/O buffering is the technique of holding data temporarily in an in-memory area while it moves between a process and a device, so the speed mismatch between fa…