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Acer 270 User Manual

Page 40

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Chapter 1

35

Switch

Power switch

Lid switch
Internet switch

Wireless ON/OFF switch

E-mail switch

Memory Address Map

Memory Address

Size

Function

00100000h-000F0000h

64KB

System BIOS

000CD000h-000C0000h

VGA BIOS

000C0000h-000A0000h

128 KB

Video memory (VRAM)

000A0000h-00000000h

640KB

Conventional memory

I/O Address Map

I/O Address

Function

000-00F

DMA controller-1

020-021

Interrupt controller-1

040-043

Timer 1

060, 064

Keyboard controller 38859 chip select

061

System speaker out

040B DMA

controller-1

061

System speaker

070-071

Real-time clock and NMI mask

080-08F

DMA page register

0A0-0A1

Interrupt controller-2

0C0-0DF

DMA controller-2

0F0-0FF

Numeric data processor

170-177

2nd EIDE device (CD-ROM) select

1F0-1F7

1st EIDE device (hard drive) select

220-22F

Audio

240-24F

Audio (optional)

278-27F

Parallel port 3

378,37A

Paraller port 1

3B0-3BB

3C0-3DF

Video Controller

3F0h-3F7

Standard Floppy Disk Controller

3F0-3F7

Floppy disk controller

480-48F, 4D6

DMA controller-1

4D0-4D1

CF8-CFF

PCI configuration register

IRQ Assignment Map

Interrupt Channel

Function(Hardware)

IRQ00

System timer

IRQ01

Keyboard

IRQ02

Programmable Interrup Controller

IRQ03

Free by default or Generic

Mechanical Specification

Item

Specification

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