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Acer 505 User Manual

Page 31

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Chapter 1

25

Memory Address Map

Memory Address

Size

Function

00000000-0009FFFF

640 KB

Base memory

000A0000-000BFFFF

128 KB

Video memory

000C0000-000CBFFF

40 KB

Video BIOS

000E0000-000FFFFF

128 KB

System BIOS

00100000-top limited

04000000-04000FFF

04001000-04001FFF

80100000-801000FF

80500000-805FFFFF

80800000-80BFFFFF

81000000-81FFFFFF

82100000-82100FFF

--

4 KB

4 KB

256 B

1 MB

3 MB

16 MB

4 MB

Extended (DIMM) memory

PCMCIA controller (slot 1)

PCMCIA controller (slot 2)

Lucent Win Modem

NetMagic VGA

Neomagic VGA

FFFF0000-FFFFFFFF

64 KB

System board extension for PnP BIOS

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 8742 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

120-13F, 180-18F

Power management controller

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

2E8-2EF

LT Win modem or COM4 (optional)

2F8-2FF

COM2 or LT Win modem(optional)

378, 37A

Parallel port 2

3BC-3BE

Parallel port 1

3B0-3BB, 3C0-3DF

Video Controller

3F0h-3F7

Standard Floppy Disk Controller

3E8-3EF

COM3 or LT Win modem (optional)

3F0-3F7

Floppy disk controller

3F8-3FF

COM1 or LT Win modem (optional)

480-48F, 4D6

DMA controller-1

4D0-4D1, CF8-CFF

PCI configuration register

505-1.book Page 25 Thursday, November 4, 1999 4:36 PM