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

 

 

 

94 Chapter 6 Specifications