System I/O |
| I/O
Address (Hex) |
System Function (Shipping Configuration) |
| 000 - 00F |
DMA Controller # 1 |
| 010 - 01F |
DMA controller aliases |
| 020 |
Interrupt Controller # 1 Control
Register |
| 021 |
Interrupt Controller #1 Mask
Register |
| 022 - 03D |
Interrupt Controller Aliases |
| 040 - 043 |
Counter/Timer |
| 044 - 04F |
Unused |
| 050-053 |
Counter/Timer Aliases |
| 053-05F |
Unused |
| 060 |
Keyboard Controller Data Register |
| 061 |
Port B: SERR/IOCHK NMI, Speaker,
Refresh |
| 062 - 063 |
Unused |
| 064 |
Keyboard Controller
Command/Status Register |
| 065 - 06F |
Unused |
| 070 |
NMI mask register (bit 7) |
| 070 |
RTC/Configuration Memory Index
Port (bit 6:0) |
| 071 |
RTC/Configuration Memory Data
Port |
| 072 |
RTC Extended Index |
| 073 |
RTC Extended Data |
| 074-07F |
Unused |
| 080 - 08F |
DMA Page Registers |
| 090 - 091 |
Unused (alias of DMA page
registers if PIIX4.4C.7=0) |
| 092 |
Port 92 (fast reset and A20 gate) |
| 093 - 09F |
Unused (alias of DMA page
registers if PIIX4.4C.7=0) |
| 0A0 |
Interrupt Controller # 2 Control
Register |
| 0A1 |
Interrupt Controller # 2 Mask
Register |
| 0A2 - 0B1 |
Unused |
| 0B2 |
APM Control |
| 0B3 |
APM Status |
| 0B4-0BF |
Unused |
| 0C0 - 0DF |
DMA Controller # 2 |
| 0E2 - 0E3 |
DDC2 Registers |
| 0E4 - 0E5 |
Master I2C Interface |
| 0E7 - 0E9 |
Unused |
| 0EA |
Ultra I/O Index Register |
| 0EB |
Ultra I/O Data Register |
| 0EC- 0EF |
Modem Configuration |
| 0F0 - 0F1 |
Coprocessor Busy Clear/Reset |
| 0F2 - 0F8 |
Unused |
| OFA |
Unused |
| 0FC-0FF |
Unused |
| 100 - 101 |
Unused |
| 102 |
Video Controller: POS 102
Register |
| 103-12F |
Unused |
| 132 - 16F |
Unused |
| 170 - 177 |
Secondary IDE Controller (CD
Drive) |
| 178 - 1EF |
Unused |
| 1F0 - 1F7 |
Primary IDE Controller (Hard
Drive) |
| 1F8 - 200 |
Unused |
| 201 |
Joystick (Decode in ES 1869) |
| 202 - 21F |
Unused |
| 220 - 22F |
Entertainment Audio |
| 230 - 25F |
Unused |
| 260 - 263 |
Reserved - Modem use during POST |
| 264 - 277 |
Unused |
| 278 - 27F |
Reserved - Parallel Port (LPT 2) |
| 280 - 2E7 |
Unused |
| 2E8 - 2EF |
Reserved - Serial Port (COM 4) |
| 2F0 - 2F7 |
Unused |
| 2F8 - 2FF |
Modem (COM 2) |
| 330 - 331 |
MPU-401 (Decode in ES 1869) |
| 332 - 36F |
Unused |
| 370 - 377 |
Reserved - Diskette Drive
Controller 2 (370-371 used for SIO lock/unlock) |
| 378 - 37F |
Parallel Port (LPT 1) |
| 380 - 387 |
Unused |
| 388 - 38B |
Audio FM Synthesizer - ES 1869 |
| 38C - 3B3 |
Unused |
| 3B4 - 3B5 |
Video Controller: Monochrome |
| 3B6 - 3B9 |
Unused |
| 3BA |
Video Controller: Monochrome |
| 3BB |
Unused |
| 3BC -3BF |
Reserved - Parallel Port |
| 3C0 -3CF |
Video Controller: VGA Registers |
| 3D0 - 3D3 |
Unused |
| 3D4 - 3D5 |
Video Controller: Color |
| 3D6 - 3D9 |
Unused |
| 3DA |
Video Controller: Color |
| 3DB - 3E7 |
Unused |
| 3E8 - 3EF |
Reserved: Serial Port (COM 3) |
| 3F0 - 3F7 |
Diskette Controller (Primary) |
| 3F6 - 3F7 |
IDE Interface (Hard disk and CD
or DVD Drive) |
| 3F8 - 3FF |
Serial Port (COM 1) |
| 4D0 |
Interrupt Controller 1 Edge/Level
Control |
| 4D1 |
Interrupt Controller 2 Edge/Level
Control |
| 4D2 - 677 |
Unused |
| 678 - 67A |
Parallel Port ECP Mode |
| 778 - 77A |
Parallel Port ECP Mode |
| CF8 |
PCI Configuration Index (32 bit
I/O only) |
| CF9 |
Reset Control |
| CFC - CFF |
PCI Configuration Data |
| 46E8 |
Video Controller:
Adapter Sleep |
