- I/O ADDRESSES
- I/O Addresses (also known as I/O Ports) are unique locations in memory that are reserved for communications between the CPU and specific physical hardware devices.
- I/O Addresses are commonly associated with specific devices and should not ordinarily be shared (just like IRQs)
- DEVICE BREAKDOWN
- The following are a few common hardware items and their associated addresses
| LINUX DEVICE | WINDOWS NAME | IRQ | I/O ADDRESS (memory) |
| /dev/ttySO | COM1 | 4 | 0x03f8 |
| /dev/lp0 | LPT1 | 7 | 0x0378-0x037f |
| /dev/fd0 | A: | 6 | 0x03f0-0x03f7 |
- DMA
- Direct Memory Addressing (DMA) is a different way of connecting to I/O Addresses
- DMA uses a direct channel to the hardware which avoids CPU interaction all together
- DMA can improve system performance by requiring less CPU activity
- As with IRQ and I/O Addresses, the DMA address should not be shared by other devices