| I/O Address | Default system function |
|---|
0000-000F | Slave DMA |
0010-0018 | System |
0001F | System |
0020-0021 | Master 8259 |
0040-0043 0048-004B | Programmable interrupt timer (PIT) #1, PIT #2 |
0050-0052 | System |
0060 | Keyboard/mouse controller |
0061 | System control port B |
0064 | Keyboard/mouse status |
0070-0071 | Nonmaskable Interrupt (NMI) enable/real-time clock |
0081-008B | DMA page registers |
0090-0091 | System |
0092 | System control port A |
0093-009F | System |
00A0-00A1 | Slave interrupt controller |
00C0-00DE | Master DMA controller |
00F0-00F1 | Coprocessor busy clear/reset |
0170-0177 | Secondary IDE controller |
01F0-01F7 | Primary IDE controller |
0201 | Joystick interface |
0220-022F | Sound Blaster |
0278-027A | LPT 2 (XT parallel port 3) |
02E8-02EF | Alternate COM (4) |
02F8-02FF | COM2 |
