| System I/O Map |
Low I/O
Address |
High I/O
Address |
Function |
Alternative
Mappings |
Device |
0000 |
000F |
DMA Controller #1 |
|
South Bridge |
0010 |
001F |
DMA Controller Aliases |
|
South Bridge |
0020 |
|
Interrupt Controller #1 Control Register |
|
South Bridge |
0021 |
|
Interrupt Controller #1 Mask Register |
|
South Bridge |
0022 |
003D |
Interrupt Controller Aliases |
|
South Bridge |
0040 |
0043 |
Counter/Timer |
|
South Bridge |
0044 |
004F |
|
|
Not used |
0050 |
0053 |
Counter/Timer Aliases |
|
South Bridge |
0053 |
005F |
|
|
Not used |
0060 |
|
Keyboard Controller Data Register |
|
South Bridge |
0061 |
|
Port B: SERR/IOCHK NMI, Speaker, Refresh |
|
South Bridge |
0062 |
0063 |
|
|
Not used |
0064 |
|
Keyboard Controller Command/Status Register |
|
South Bridge |
0065 |
006F |
|
|
Not Used |
0070 |
|
NMI Mask Register (Bit 7) |
|
South Bridge |
0070 |
|
RTC/Configuration Memory Index Port (Bit 6:0) |
|
South Bridge |
0071 |
|
RTC/Configuration Memory Data Port |
|
South Bridge |
0072 |
|
RTC Extended Index |
|
South Bridge |
0073 |
|
RTC Extended Data |
|
South Bridge |
0074 |
007F |
|
|
Not Used |
0080 |
008F |
DMA Page Registers |
|
South Bridge |
0090 |
0091 |
Alias of DMA page registers if SOUTH
BRIDGE.4C.7=0 |
|
South Bridge
Not Used |
0092 |
|
Port 92 (fast reset and A20 gate) |
|
South Bridge |
0093 |
009F |
Alias of DMA page registers if SOUTH
BRIDGE.4C.7=0 |
|
South Bridge
Not used |
00A0 |
|
Interrupt Controller #2 Control Register |
|
South Bridge |
00A1 |
|
Interrupt Controller #2 Mask Register |
|
South Bridge |
00A2 |
00B1 |
|
|
Not Used |
00B2 |
|
APM Control |
|
South Bridge |
00B3 |
|
APM Status |
|
South Bridge |
00B4 |
00BF |
|
|
Not Used |
00C0 |
00DF |
DMA Controller #2 |
|
South Bridge |
Accessories
