Acer ALTOS 900 User Manual

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System Board

1.1 Features

This high-perf ormance system board is designed to support the Intel P54C and P55C CPUs running at 75/100/120/133/150/ 166/200 MHz. It utilizes both the EISA and the PCI local bus architecture. Three EISA and four PCI bus slots reside on the board to al low installat ion of either master or slave devices, except for one PCI slot that supports only slave dev ices.

The board has three memory banks composed of two 72-pin SIMM sockets each that support a maximum system memory of 192 MB using 32-MB SIMMs. The SIMM sockets support both EDO and fastpage mode SIMMs. A second-level cache socket is available for a 256-KB or 512-KB synchronous SRAM module.

A 50-pin Fast SCSI-II int erface with 10 MB/s transfer rate and a 68pin W ide SCSI interf ace that transfer s at 20 MB/s (W ide SCSI ) and 40 MB/s (Ultra SCSI) com e with the system board to connect SCSI devi ces. Standard I/O features such as two serial interfaces (COM1, COM2), one paral lel port interf ace, an IDE dri ve i nterf ace, a disket te driv e interf ace, and PS/2 mouse and keyboard c onnectors reside on the system board.

The system board supports two optional f eatures, the ASM Pro and the Remote Diagnostic Management (RDM) for better server management. These features maximize the system operating time by minimi z ing the downtime.

System Board 1-1

1.2 Major Components

The system board has the following major components:

•

One zero-insertion force (ZIF) socket for Intel P54C or P55C CPU

•

Three mem ory banks (Bank 1 to Bank 3) com posed of six 72-pi n SIMM sockets

•

Synchronous cache module socket that supports 256 KB and 512 KB second-level cache

•

Three EISA and four PCI expansion slots

•

256-KB Flash ROM for system BIOS

•

RTC chip that contains clock/calendar plus 128 bytes CMOS RAM with battery backup

•

50-pin Fast SCSI-II and 68-pin W ide SCSI interfaces

•

Two 24-pin RDM int er faces

•

IDE hard disk and di sket te drive inter faces

•

Onboard VRAM pl us a VRAM socket for video memory upgr ade

•

Power connector f or 200- watt switc hing power supply

•

I/O, SCSI, VGA, memory, and ASM Pro controller chipsets

•

External ports:

• PS/2-compatibl e k ey boar d por t

• PS/2-compatibl e mouse port

1-2 User’s Guide

1.2.1 System Board Layout

1 PS/2 keyboard connector 2 PS/2 mouse connector 3 PCI slots 4 Keyboard controller 5 EISA slots 6 Video RAM 7 Video RAM upgrade socket

8 CPU voltage regulator 9 Buzzer 10 CPU socket 11 CPU voltage regulator 12 Cache module socket 13 SIMM sockets

Figure 1-1 System Board Layout

System Board 1-3

1.3 Jumpers and Connectors

1.3.1 Jumper and Connector Locations

Figure 1-2 shows the jumper locations on the system board. The blackened pin on a jumper repr esents pi n 1.

Figure 1-2 Jumper Locat ions

Jumpers are prefixed “JP”. Connectors are prefixed “CN”. FA 1 to FA5 are fan connectors.

The blackened pin of a jumper r epr es ents pin 1.

1-4 User’s Guide

1.3.2 Jumper Settings

Table 1-1 Jumper Settings

Jumper Setting Function

CPU Voltage

JP1 1-2

Cache Size

JP3 1-2*

BIOS Versio n

JP8 1-2*

Password Security

JP9 1-2

PC Sound Source

JP10 1-2*

Front Panel Reset

JP11 1-2*

CPU Type

JP17, JP18, JP19 1-2

SCSI Selection

JP20 1-2*

Onboard VGA

JP23 1-2*

2-3

2-3*

2-3

2-3*

2-3 4-5

2-3

VR VRE

256 KB 512 KB

Acer Generic

Enabled Bypass

Buzzer Speaker

Enabled Disabled

P55C CPU P54C CPU

PCI device ID is 11 Hex PCI device ID is 0C Hex Disabled

Enabled Disabled

Default setting

System Board 1-5

Table 1-1 Jumper Settings ( c ontinued)

Jumper Setting Function

SCSI Termi n ation

JP24 1-2*

Core/Bus Freq.

JP4, JP5, JP7

2-3

JP4 JP5 JP7

2-3 2- 3 1-2 1-2 1- 2 2-3

2-3 1- 2 2-3 2-3 2- 3 2-3

High-byte terminat or O N High-byte terminat or O FF

Bus Freq. Core Freq. Ratio

50 MHz 75 MHz 3/2 60 MHz 150 MHz 5/2

60 MHz 120 MHz 2/1 60 MHz 90 MHz 3/2

1-2 2- 3 3-4 1-2 1- 2 3-4 2-3 1- 2 3-4 2-3 2- 3 3-4

66 MHz 200 MHz 3/1 66 MHz 166 MHz 5/2 66 MHz 133 MHz 2/1 66 MHz 100 MHz 3/2

1-6 User’s Guide

1.3.3 Connector Functions

Table 1-2 l ists the dif f erent c onnectors on the system board and their respective func tions.

Table 1-2 Connector Funct ions

Connector Function

CN1 COM1 CN2 COM2 CN3 Power connector for 200- watt SPS CN4 Power connector for 300- watt SPS CN5 Parallel port connector CN6 Diskette drive connector CN7 IDE drives connector CN8 Remote diagnostic module (RDM) connector

CN9 Remote diagnostic module (RDM) connector CN10 Faulty-drive LED connector CN11 Fast SCSI-II (narrow SCSI) connector CN12 Wi de SCSI connector CN13 VGA daughter board connector CN15 Power LED and keylock connector CN16 Hard disk LED connector CN17 Speaker connector CN18 Reset/Turbo connector

System Board 1-7

1.4 ESD Precautions

Always observe the following ESD (electrostatic discharge) precautions before installing any system c omponent:

1. Do not remove any system com ponent from it s packagi ng unless you are ready to i nstall it.

2. Wear a wrist grounding strap before handling electronic components. Wrist grounding straps are available at most electronic component stor es.

DO NOT attempt the procedur es in the following sect ions unles s y ou ar e c onfident of your capability to per form them. Otherwise, ask a service tec hnic ian for assistance.

1-8 User’s Guide

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