What are IRQs, I/O, DMA and Memory addresses?
These are hardware resources used by devices to talk to the CPU. Some devices such as ISA, PCI and AGP cards will be allocated an Interrupt Request Queue number so that the system knows which device to talk to, IRQs are allocated to each slot, port or other device on startup. An I/O or Input/Output port is another channel used by the device to talk to the CPU . DMA or Direct Memory Access is used by devices to directly access memory and avoid using the CPU e.g. Hard Disks and FDD controllers. Memory addresses are used to store temporary data such as buffers for I/O devices e.g. Network cards and Modems.