Specifications

System I/O address specifications
I/O address (hex) System function (shipping configuration)
000 - 00F DMA controller no. 1
010 - 01F Unused
020 - 021 Interrupt controller no. 1
022 - 024 Opti chipset configuration registers
025 - 03F Unused
02E - 02F 87334 “Super I/O” configuration for CPU
040 - 05F Counter/timer registers
044 - 05F Unused
060 Keyboard controller
061 Port B
062 - 063 Unused
064 Keyboard controller
065 - 06F Unused
070 - 071 NMI enable/RTC
072 - 07F Unused
080 - 08F DMA page registers
090 - 091 Unused
092 Port A
093 - 09F Unused
0A0 - 0A1 Interrupt controller no. 2
I/O Address (hex) System function (shipping configuration)
0A2 - 0BF Unused
0C0 - 0DF DMA controller no. 2
0E0 - 0EF Unused
0F0 - 0F1 Coprocessor busy clear/reset
0F2 - 0FF Unused
100 - 16F Unused
170 - 177 Secondary fixed disk controller
178 - 1EF Unused
1F0 - 1F7 Primary fixed disk controller
1F8 - 200 Unused
201 JoyStick (decoded in ESS1688)
202 - 21F Unused
System I/O address specifications 87