ASUS PI-P55T2P4 User Manual

R

P/I-P55T2P4

Pentium Motherboard

USER'S MANUAL

USER'S NOTICE

No part of this product, including the product and software may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any lan­guage in any form by any means without the express written permission of ASUSTeK
COMPUTER INC. (hereinafter referred to as ASUS) except documentation kept
by the purchaser for backup purposes.

Specifications are subject to change without notice. ASUS provides this manual
“as is” without warranty of any kind, either express or implied, including but not
limited to the implied warranties or conditions of merchantability or fitness for a
particular purpose. In no event shall ASUS be liable for any loss or profits, loss of
business, loss of use or data, interruption of business, or for indirect, special, inci­dental, or consequential damages of any kind, even if ASUS has been advised of
the possibility of such damages arising from any defect or error in this manual or
product. ASUS may revise this manual from time to time without notice.

Products mentioned in this manual are mentioned for identification purposes only.
Product names appearing in this manual may or may not be registered trademarks
or copyrights of their respective companies.

• Intel, LANDesk, and Pentium are registered trademarks of Intel Corporation.

• IBM is a registered trademark of International Business Machines Corp.

• Symbios is a registered trademark of Symbios Logic Corporation.

• Windows and MS-DOS are registered trademarks of Microsoft Corporation.

• Sound Blaster AWE32 and SB16 are trademarks of Creative Technology Ltd.

• Adobe and Acrobat are registered trademarks of Adobe Systems Incorporated.
The product name and revision number are both printed on the board itself. Manual

revisions are released for each board design represented by the digit before and
after the period of the manual revision number . Manual updates are represented by
the third digit in the manual revision number. For previous or updated manuals,
BIOS, drivers, or product release information you may visit the ASUS home page
at http://www.asus.com.tw/ or contact ASUS from the following page.

© Copyright 1997 ASUSTeK COMPUTER INC. All rights reserved.

II

Product Name: ASUS P/I-P55T2P4
Manual Revision: 3.11
Release Date: May 1997

ASUS P/I-P55T2P4 User's Manual

ASUS CONTACT INFORMATION

ASUSTeK COMPUTER INC.

Marketing Info:

Address: 150 Li-Te Road, Peitou, Taipei, Taiwan, ROC
Telephone: [phone]
Fax: [phone]
Email: [e-mail]

Technical Support:

Fax: [phone]
BBS: 886-2-896-4667
Email: [e-mail]
WWW: http://www.asus.com.tw/
Gopher: gopher.asus.com.tw
FTP: ftp.asus.com.tw/pub/ASUS

ASUS COMPUTER INTERNATIONAL

Marketing Info:

Address: 721 Charcot Avenue, San Jose, CA 95131, USA
Telephone: [phone]
Fax: [phone]
Email: [e-mail]

Technical Support:

BBS: 1-408-474-0555
Email: [e-mail]

ASUS COMPUTER GmbH

Marketing Info:

Address: Harkort Str. 25, 40880 Ratingen, BRD, Germany
Telephone: [phone]
Fax: [phone]
Email: [e-mail]

Technical Support:

BBS: 49-2102-448690
Email: [e-mail]

ASUS P/I-P55T2P4 User's Manual

III

CONTENTS

I. INTRODUCTION......................................................... 1

How this manual is organized .......................................................... 1

Item Checklist .................................................................................. 1

II. FEATURES .................................................................. 2

Features of the ASUS Motherboard ................................................. 2

Parts of the ASUS Motherboard ...................................................... 3

III. INSTALLATION ........................................................ 4

Map of the Motherboard .................................................................. 4

Installation Steps .............................................................................. 6

1. Jumpers ........................................................................................ 6

Jumper Settings .................................................................... 7

Cyrix CPU Identification ...................................................... 11

2. System Memory (DRAM & SRAM) .......................................... 12

TAG SRAM Upgrade: .......................................................... 12

DRAM Memory Installation Procedures: ............................ 13

Static RAM (SRAM) for Level 2 (External) Cache ................... 14

Compatible Cache Modules for this Motherboard ............... 14

3. Central Processing Unit (CPU) ................................................... 15

4. Expansion Cards ......................................................................... 16

Expansion Card Installation Procedure: ............................... 16

Assigning IRQs for Expansion Cards................................... 16

Assigning DMA Channels for ISA Cards ............................. 17

ASUS MediaBus Card .......................................................... 18

5. External Connectors .................................................................... 19

Power Connection Procedures ................................................... 25

IV. BIOS SOFTWARE ..................................................... 26

Support Software ............................................................................. 26

Flash Memory Writer Utility ........................................................... 26

Main Menu ........................................................................... 26

Advanced Features Menu ..................................................... 27

Updating your Motherboard's BIOS .......................................... 28

IV

6. BIOS Setup ................................................................................. 29

Load Defaults ....................................................................... 30

Standard CMOS Setup ............................................................... 30

ASUS P/I-P55T2P4 User's Manual

CONTENTS

Details of Standard CMOS Setup: ........................................ 31

BIOS Features Setup .................................................................. 34

Details of BIOS Features Setup:........................................... 34

Chipset Features Setup ............................................................... 37

Power Management Setup.......................................................... 40

Details of Power Management Setup: .................................. 40

PNP and PCI Setup .................................................................... 42

Load BIOS Defaults ................................................................... 44

Load Setup Defaults ................................................................... 44

Supervisor Password and User Password .................................. 45

IDE HDD Auto Detection .......................................................... 46

Save and Exit Setup ................................................................... 47

Exit Without Saving ................................................................... 47

V. DESKTOP MANAGEMENT ...................................... 49

Desktop Management Interface (DMI) ............................................ 49

Introducing the ASUS DMI Configuration Utility ............... 49

System Requirements ........................................................... 49

Using the ASUS DMI Configuration Utility ........................ 50

Notes: .................................................................................... 50

VI. ASUS PCI-SC200 SCSI Card....................................53

NCR SCSI BIOS and Drivers .......................................................... 53

The ASUS PCI-SC200 SCSI Interface Card ................................... 54

Setting Up the ASUS PCI-SC200 .............................................. 54

Setting the INT Assignment ....................................................... 55

Terminator Settings .................................................................... 55

SCSI ID Numbers ...................................................................... 56

VII. ASUS I-A16C Audio Card ....................................... 57

ASUS I-A16C Audio Features ................................................... 57

Unpacking and Handling Precautions ........................................ 57

Layout and Connectors .............................................................. 58

Connectors ............................................................................ 58

CD-Audio Connector Pin Definitions ........................................ 58

VIII. DOS 3.1 & Windows 3.1x Audio Software

(with optional ASUS I-A16C Audio Card Bundle Only)

IX. Windows 95 Audio Software

(with optional ASUS I-A16C Audio Card Bundle Only)

ASUS P/I-P55T2P4 User's Manual

V

FCC & DOC COMPLIANCE

Federal Communications Commission Statement

This device complies with FCC Rules Part 15. Operation is subject to the following
two conditions:

• This device may not cause harmful interference, and

• This device must accept any interference received, including interference that
may cause undesired operation.

This equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful interference in a residential installa­tion. This equipment generates, uses and can radiate radio frequency energy and, if
not installed and used in accordance with manufacturer's instructions, may cause
harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can be determined by
turning the equipment off and on, the user is encouraged to try to correct the inter­ference by one or more of the following measures:

• Re-orient or relocate the receiving antenna.

• Increase the separation between the equipment and receiver.

• Connect the equipment to an outlet on a circuit different from that to which
the receiver is connected.

• Consult the dealer or an experienced radio/TV technician for help.

WARNING: The use of shielded cables for connection of the monitor to the graphics
card is required to assure compliance with FCC regulations. Changes or modifica­tions to this unit not expressly approved by the party responsible for compliance
could void the user's authority to operate this equipment.

Canadian Department of Communications Statement

This digital apparatus does not exceed the Class B limits for radio noise emissions
from digital apparatus set out in the Radio Interference Regulations of the Cana­dian Department of Communications.

VI

ASUS P/I-P55T2P4 User's Manual

I. INTRODUCTION

How this manual is organized

This manual is divided into the following sections:

I. Introduction: Manual information and checklist
II. Features: Information and specifications concerning this product
III. Installation: Instructions on setting up the motherboard.
IV. BIOS Setup: BIOS software setup information.
V. Software: Information on the included support software
VI. ASUS SCSI: Installation of an optional ASUS SCSI cards
VII. ASUS I-A16C: Installation of an optional 16-bit Audio card
VIII. DOS/Win3.1x: Audio Software Manual (with ASUS I-A16C bundle)
IX. Windows 95: Audio Software Manual (with ASUS I-A16C bundle)

Item Checklist

Please check that your package is complete. If you discover damaged or missing
items, please contact your retailer.

I. INTRODUCTION

(Manual / Checklist)

þ The ASUS P/I-P55T2P4 motherboard
þ 2 serial port ribbon cables attached to a mounting bracket
þ 1 parallel ribbon cable with mounting bracket
þ 1 IDE ribbon cable
þ 1 floppy ribbon cable
þ Support drivers and utilities as follows:

• Flash Memory Writer utility to update the FLASH BIOS

• Desktop Management Interface (DMI) utility

• Bus Master IDE Drivers for various operating systems

• Audio drivers and utilities (included with ASUS I-A16C audio bundle only)

• Readme files for descriptions and use of the files

• Technical Support Form

þ This user's manual (Audio sections included with ASUS I-A16C audio bundle)
¨ Optional infrared module
¨ Optional ASUS PCI-SC200 Fast-SCSI or PCI-SC860 Ultra-Fast SCSI card
¨ Optional ASUS I-A16C audio card
¨ Optional PS/2 mouse cable with mounting bracket
¨ Optional ASUS pipelined burst cache module

ASUS P/I-P55T2P4 User’s Manual 1

II. FEATURES

(Features)

II. FEATURES

Features of the ASUS Motherboard

The ASUS P/I-P55T2P4 is carefully designed for the demanding PC user who wants
a great many features in a small package. This motherboard:

• Easy Installation: Is equipped with BIOS that supports auto detection of hard

drives and Plug and Play to make setup of hard drives and expansion cards
virtually automatic.

• V ersatile Processor Support: Intel Pentium

P54CS), IBM®/Cyrix® 6x86-PR166+ (Rev 2.7 or later), IBM®/Cyrix® 6x86MX
(PR166 & above), AMD-K5™ (PR75-PR133), AMD-K6™ (PR166-PR233).

• Intel Chipset: Features Intel's 430HX PCIset with I/O subsystems.

• Error Checking and Corr ecting (ECC): Using Intel's 430HX PCIset together

with parity DRAM modules can detect multi-bit memory errors and correct 1­bit memory errors.

• Desktop Management Interface (DMI): Supports DMI through BIOS which

allows hardware to communicate within a standard protocol creating a higher
level of compatibility (see section V).

®

75-233MHz (P55C-MMX™, P54C/

™

• L2 Cache: Provides the option of 0KB upgradeable to 256KB or 512KB, on-

board 256KB upgradeable to 512KB, or 512KB onboard Pipelined Burst SRAM.
Upgrades are made through a Synchronous SRAM cache module. (See page

14 for compatible cache modules.)

• Versatile DRAM Memory Support: Supports 72-pin SIMMs of 4MB, 8MB,

16MB, 32MB, or 64MB to form a memory size between 8MB to 256MB. Sup­ports both Fast Page Mode (FPM) and Extended Data Output (EDO) SIMMs.

• ISA and PCI Expansion Slots: Provides three 16-bit ISA slots, three 32-bit

PCI slots, and one PCI/MediaBus 2.0 which allows the use of either a standard
PCI card or the ASUS MediaBus Card.

• ASUS MediaBus Rev 2.0: Features an expansion slot extension shared with

PCI Slot 4 for an optional high-performance expansion card which includes two
functions in one easy-to-install card. (For revision compatibility informa-

tion, please refer to page 18.)

• Super Multi-I/O: Provides two high-speed UART compatible serial ports and

one parallel port with EPP and ECP capabilities. UART2 can also be directed
from COM2 to the Infrared Module for wireless connections. T wo floppy drives
of either 5.25" or 3.5" (1.44MB or 2.88MB) are also supported without an exter­nal card. The Japanese "Floppy 3 mode" (3.5" 1.2MB) floppy standard is

also supported.

2 ASUS P/I-P55T2P4 User’s Manual

II. FEATURES

• PCI Bus Master IDE Controller: Comes with an onboard PCI Bus Master
IDE controller with two connectors that supports four IDE devices in two chan­nels, provides faster data transfer rates, and supports Enhanced IDE devices
such as T ape Backup and CD-ROM drives. This controller supports PIO Modes
3 and 4 and Bus Master IDE DMA Mode 2. BIOS supports IDE CD-ROM

and SCSI bootup.

• Optional IrDA and PS/2 Mouse Connector: This motherboard supports an
optional infrared port module for wireless interface and a PS/2 mouse cable set.

• NCR SCSI BIOS: This motherboard has firmware that supports the optional
ASUS PCI-SC200 SCSI controller cards.

Parts of the ASUS Motherboard

3 ISA Slots

Programmable
Flash ROM

3 PCI Slots

Super Multi-I/O
Onboard Floppy

& IDE Connect.

PCI 4 or ASUS
MediaBus 2.0

(4) 72-pin SIMM
Sockets

Upgradeable
TAG SRAM

Self-Powered
RealTime Clock

Intel's 430HX
PCIset

Parallel & Serial Ports

II. FEATURES

(Parts of Board)

CPU ZIF Socket 7

L2 Upgrade
Cache
Expansion Slot

Onboard 256KB/
512KB Pipelined
Burst L2 Cache

ASUS P/I-P55T2P4 User’s Manual 3

III. INSTALLATION

Map of the ASUS Motherboard

III. INSTALLATION

(Map of Board)

ISA Slot 3

ISA Slot 2

ISA Slot 1

JP2

Boot Block Write (Dis/En)

PCI Slot 4

PCI Slot 3

MediaBus 2.0

Universal Serial Bus
(Reserved for future use)

PCI Slot 2

PCI Slot 1

MULTI I/O
Chipset

Floppy Drives

PS/2 Mouse

Multi-I/O
(En/Dis)

Primary IDE

Secondary IDE

COM 1

Serial (COM) Ports

Parallel (Printer) Port

SIMM Socket 1 (Bank 0)

JP1

Board Power Input

P9

P8

SIMM Socket 2 (Bank 0)

Keyboard

COM 2

SIMM Socket 3 (Bank 1)

SIMM Socket 4 (Bank 1)

CMOS Operation/Clear

Case Connector

IDE LED

Infrared Conn.

CPU VCore

JP20

JP7

JP10

BUS Freq

Freq Ratio

12V Fan Power

JP17

Voltage (STD/VRE)

JP9

JP8

JP12

Pipelined Burst Level 2 Cache Expansion Slot

JP4

Cacheable
64/512MB

TAG SRAM Upgrade

CPU ZIF Socket 7

JP11

JP5

L2 Cache Size (256/512)

256/512KB onboard L2 Cache

4 ASUS P/I-P55T2P4 User’s Manual

III. INSTALLATION

Jumpers

1) JP1 p. 7 Multi-I/O Selection (Enable/Disable)

2) JP2 p. 7 Flash ROM Boot Block Program (Disable/Enable)

3) JP5 p. 8 Total Level 2 Cache Size Setting (256/512KB)

4) JP7 p. 8 Real Time Clock RAM (Operation/Clear Data)

5) JP17 p. 9 Single Power Plane CPU Voltage Selection

6) JP20 p. 9 Dual Power Plane CPU Voltage Selection

7) JP8, JP9,JP10 p. 10 CPU External Clock (BUS) Frequency Selection

8) JP11, JP12 p. 10 CPU:BUS Frequency Ratio

9) JP4 p. 11 Memory Cacheable Size (64MB / 512MB)

Expansion Slots

1) SIMM Sockets p. 12 DRAM Memory Expansion Sockets

2) TAG SRAM p. 12 Upgrade socket for TAG SRAM

3) Cache Expansion p. 14 Socket for Pipelined Burst SRAM Cache Module

4) CPU ZIF Socket 7 p. 15 Socket for Central Processing Unit (CPU)

5) ISA Slots 1, 2, 3 p. 16 16-bit ISA Bus Expansion Slots

6) PCI Slots 1, 2, 3 p. 16 32-bit PCI Bus Expansion Slots

7) PCI 4 / MediaBus p. 18 32-bit PCI Bus Slot and MediaBus

(Map of Board)

III. INSTALLATION

Connectors

1) Keyboard p. 19 Keyboard Connector (5-pin Female)

2) PS/2 Mouse p. 19 PS/2 Mouse Connector (6-pin Block)

3) Parallel Port p. 20 Parallel Port Connector (26-pin Block)

4) Serial Port p. 20 Serial Port COM1 & COM2 (10-pin Blocks)

5) Floppy Drive p. 21 Floppy Drive Connector (34-pin Block)

6) Power Input p. 21 Motherboard Power Connector (12-pin Block)

7) Primary/Second. IDE p. 22 Primary/Secondary IDE Connectors (40-pin Blocks)

8) IDE LED p. 22 IDE LED Activity Light

9) Turbo/Power (CON1) p. 23 Turbo LED/Power LED (2-pins)

10) SMI Switch (CON1) p. 23 SMI Switch Lead (2-pins)

11) Reset Switch (CON1) p. 23 Reset Switch Lead (2-pins)

12) Key Lock (CON1) p. 23 Keyboard Lock Switch Lead (5-pins)

13) Speaker (CON1) p. 23 Speaker Connector (4-pins)

14) FAN p. 24 CPU 12V Cooling Fan Connector

15) IR CON p. 24 Infrared Port Module Connector

ASUS P/I-P55T2P4 User's Manual 5

III. INSTALLATION

III. INSTALLATION

Installation Steps

Before using your computer, you must complete the following steps:

1. Set Jumpers on the Motherboard

2. Install DRAM and SRAM Modules

3. Install the Central Processing Unit (CPU)

4. Install Expansion Cards

5. Connect Ribbon Cables, Cabinet Wires, and Power Supply

6. Setup the BIOS Software

1. Jumpers

Several hardware settings are made through the use of jumper caps to connect jumper
pins (JP) on the motherboard. See "Map of the Motherboard" on page 4 for loca­tions of jumpers. The jumper settings will be described numerically such as [----],

(Jumpers)

[1-2], [2-3] for no connection, connect pins 1&2, and connect pins 2&3 respec­tively. Pin 1 for our motherboards is always on top
holding the motherboard with the keyboard connector away from yourself. A "1" is
written besides pin 1 on jumpers with three pins. The jumpers will also be shown
graphically such as to connect pins 1&2 and to connect pins 2&3.
Jumpers with two pins will be shown as for Short (On) and for Open
(Off). For manufacturing simplicity, the jumpers may be sharing pins from other
groups. Use the diagrams in this manual instead of following the pin layout on the
board. Settings with two jumper numbers require that both jumpers be moved to­gether. To connect the pins, simply place a plastic jumper cap over the two pins as
diagramed.

WARNING: Computer motheboards and components contain very delicate
Integrated Circuit (IC) chips. To protect the motherboard and other compo­nents against damage from static electricity, you should follow some precau­tions whenever you work on your computer.

1. Unplug your computer when working on the inside.

2. Hold components by the edges and try not to touch the IC chips, leads, or
circuitry.

3. Use a grounded wrist strap before handling computer components.

4. Place components on a grounded antistatic pad or on the bag that came with
the component whenever the components are separated from the system.

Pin 1

or on the left

Pin 1

when

ASUS P/I-P55T2P4 User's Manual6

III. INSTALLATION

Jumper Settings

1. Onboard Multi-I/O Selection (JP1)

You can selectively disable each onboard Multi-I/O item (floppy, serial, paral­lel, and IrDA) through BIOS (see CHIPSET FEATURES SETUP) or disable all
Multi-I/O items at once with the following jumper in order to use your own
Multi-I/O card.

Selections JP1

Enable [1-2] (Default)
Disable [2-3]

JP1

1
2
3

Enable (Default) Disabled

Multi I/O Setting (Enable / Disable)

JP1

1
2
3

2. Flash ROM Boot Block Programming (JP2)

This sets the operation mode of the boot block area of the BIOS Flash ROM to
allow programming in the Enabled position.

Programming JP2

Disabled [1-2] (Default)
Enabled [2-3]

JP2

1

23 123

Disabled (Default) Enabled

JP2

(Jumpers)

III. INSTALLATION

Boot Block Programming (Disable / Enable)

ASUS P/I-P55T2P4 User's Manual 7

III. INSTALLATION

3. Total Level 2 Cache Size Setting (JP5)

This jumper sets the total amount of L2 cache that is present. If you have both
onboard cache chips (see "Map of Motherboard" for locations) and a Cache
Expansion Slot, then you have 256KB. If you only have onboard cache chips,
then you have 512KB. An "ASUS" or "COAST" cache module can be used to
upgrade the 256KB version to 512KB. If there is no onboard cache, you may
install a cache module of either 256KB or 512KB. IMPORTANT: See page
14 "SRAM Cache" for installation procedures. Regardless of your cache
combination, set the following jumpers according to the total amount of L2
cache that is present onboard and installed as a module.

Selections JP5

256KB [1-2]
512KB [2-3]

III. INSTALLATION

(Jumpers)

JP5

1
2
3

256KB 512KB

Total L2 Cache Size Setting (256KB / 512KB)

JP5

1
2
3

4. Real Time Clock (RTC) RAM (JP7)

This clears the user-entered information stored in the CMOS RAM of the Real
Time Clock such as hard disk information and passwords. To clear the RTC
data: (1) Turn off the PC, (2) Short this jumper, (3) Power on the PC, (4) Turn
off the PC, (5) Remove this jumper, (6) Power on the PC, (7) Hold down <De­lete> during bootup and enter BIOS setup to re-enter user preferences.

Selections JP7

Operation [open] (Default)
Clear Data [short] (momentarily)

JP7

Operation (Default) Clear Data

RTC RAM (Operation / Clear Data)

JP7

ASUS P/I-P55T2P4 User's Manual8

III. INSTALLATION

5-6. Single/Dual Power Plane CPU Voltage Regulator Selections

The following jumpers set the voltage supplied to the CPU. Determine whether
your CPU has a Single Power Plane or Dual Power Planes and then the volt­age that it uses. When a single power plane CPU is installed, the dual power
plane selections will be automatically disabled. When a dual power plane CPU
is installed, the single power plane selections will be automatically disabled.
You may have one jumper on the Single Power Plane and another on the Dual

Power Planes at the same time.
WARNING: Incorrect setting can damage your CPU. If you are not

exactly clear on CPU jumper settings, check with your retailer.

5. Single Power Plane CPU Voltage Regulator Selection (JP17)

These jumpers set the voltage supplied to single power plane CPU's.

CPU Manufacturer CPU Type V oltage JP17

Intel/AMD P54C/CS/K5 STD (3.4 Volts) [1-2] (Default)
Intel/AMD/IBM/Cyrix P54C/CS/K5/6x86 VRE (3.5 Volts) [2-3]

JP17

1

23

P54C/CS/K5
(STD 3.4V) (Default)

Voltage Regulator Output Selection (STD / VRE)

JP17

123

P54C/CS/K5/6x86
(VRE 3.5 Volts)

6. Dual Power Plane CPU Voltage Regulator Selection (JP20)

These jumpers set the voltage supplied to dual power plane CPU's.

CPU Manufacturer CPU Type V oltage JP20

AMD K6-PR233 3.2 Volts [9-10]
AMD K6-PR166,200 2.9 Volts [7-8]
Intel/IBM/Cyrix P55C/6x86MX 2.8 Volts [5-6] (Default)
(Reserved) (Reserved) 2.7 Volts [3-4]
(Reserved) (Reserved) 2.5 Volts [1-2]

[9-10]

JP20

[7-8]

JP20

[5-6]

JP20

(Jumpers)

III. INSTALLATION

K6-PR233
(3.2 Volts)

CPU Vcore Voltage Selection

K6-PR166,200
(2.9 Volts)

P55C/6x86MX
(2.8V) (Default)

ASUS P/I-P55T2P4 User's Manual 9

III. INSTALLATION

7. CPU External (BUS) Frequency Selection (JP8, JP9, JP10)

These jumpers tell the clock generator what frequency to send to the CPU. These
allow the selection of the CPU’ s External frequency (or BUS Clock). The BUS Clock
times the BUS Ratio equals the CPU's Internal frequency (the advertised CPU speed).

8. CPU to BUS Frequency Ratio (JP11, JP12)

These jumpers set the frequency ratio between the Internal frequency of the CPU
and the External frequency (called the BUS Clock) within the CPU. These must

be set together with the above jumpers CPU External (BUS) Frequency Selection.

JP9

JP8

JP10

JP9

JP10

JP8

JP9

JP10

JP8

JP9

JP10

JP8

JP9

JP10

JP8

III. INSTALLATION

(Jumpers)

JP12

1
2
3

75MHz

JP11

JP12

1
2
3

3.0x(3/1)

3.0x(3/1)

4.0x(4/1)

1
2
3

JP11

1
2
3

Complete Names:

Intel Pentium P54C, P55C-MMX
AMD K5, K6
IBM/Cyrix 6x86, 6x86MX

JP12

JP11

2.0x(2/1)

2.0x(2/1)

2.0x(2/1)

1
2
3

66MHz

1
2
3

2.5x(5/2)

2.5x(5/2)

1.0x(1/1)

1
2
3

50MHz 55MHz 60MHz

CPU External Clock (BUS) Frequency Selection

P54C/K5
P55C/K6/MX
IBM/Cyrix 6x86

CPU : BUS Frequency Ratio

1
2
3

JP12

JP11

1.5x(3/2)

3.5X(7/2)

3.0x(3/1)

1
2
3

Set the jumpers by the Internal speed of the Intel, AMD, IBM, or Cyrix CPU as follows:

(BUS Freq.) (Freq. Ratio)

CPU Model Freq. Ratio B. Freq. JP10 JP9 JP8 JP12 JP11

Intel Pentium 233MHz 3.5x 66MHz [2-3] [1-2] [2-3] [1-2] [1-2]
Intel Pentium 200MHz 3.0x 66MHz [2-3] [1-2] [2-3] [2-3] [1-2]
Intel Pentium 166MHz 2.5x 66MHz [2-3] [1-2] [2-3] [2-3] [2-3]
Intel Pentium 150MHz 2.5x 60MHz [1-2] [2-3] [2-3] [2-3] [2-3]
Intel Pentium 133MHz 2.0x 66MHz [2-3] [1-2] [2-3] [1-2] [2-3]
Intel Pentium 120MHz 2.0x 60MHz [1-2] [2-3] [2-3] [1-2] [2-3]
Intel Pentium 100MHz 1.5x 66MHz [2-3] [1-2] [2-3] [1-2] [1-2]
Intel Pentium 90MHz 1.5x 60MHz [1-2] [2-3] [2-3] [1-2] [1-2]
Intel Pentium 75MHz 1.5x 50MHz [2-3] [2-3] [2-3] [1-2] [1-2]

AMD-K6-PR233 233MHz 3.5x 66MHz [2-3] [1-2] [2-3] [1-2] [1-2]
AMD-K6-PR200 200MHz 3.0x 66MHz [2-3] [1-2] [2-3] [2-3] [1-2]
AMD-K6-PR166 166MHz 2.5x 66MHz [2-3] [1-2] [2-3] [2-3] [2-3]

AMD-K5-PR133/100 100MHz 1.5x 66MHz [2-3] [1-2] [2-3] [1-2] [1-2]
AMD-K5-PR120/90 90MHz 1.5x 60MHz [1-2] [2-3] [2-3] [1-2] [1-2]
AMD-K5-PR75 75MHz 1.5x 50MHz [2-3] [2-3] [2-3] [1-2] [1-2]

IBM/Cyrix 6x86MX-PR233 200MHz 3.0x 66MHz [2-3] [1-2] [2-3] [2-3] [1-2]
IBM/Cyrix 6x86MX-PR200 166MHz 2.5x 66MHz [2-3] [1-2] [2-3] [2-3] [2-3]
IBM/Cyrix 6x86MX-PR166 150MHz 2.5x 60MHz [1-2] [2-3] [2-3] [2-3] [2-3]

*IBM/Cyrix6x86-PR166+ 133MHz 2.0x 66MHz [2-3] [1-2] [2-3] [1-2] [2-3]
*NOTE: Only IBM or Cyrix Rev 2.7 or later is supported on this motherboard (see next page). Bootup

screen will show 6x86-P166+ with the Cyrix PR166+ installed on this motherboard.

ASUS P/I-P55T2P4 User's Manual10

III. INSTALLATION

Compatible Cyrix CPU Identification

The only Cyrix CPU that is supported on this motherboard is
labeled Cyrix 6x86-PR166+ but must be Revision 2.7 or later .
Look on the underside of the CPU for the serial number . The
number should read G8DC6620A or later.

9. Memory Cacheable Size (JP4)

The default of 64MB uses only the onboard T AG SRAM which allows cacheable

memory up to 64MB. If you install DRAM above 64MB and wish to allow
cacheable memory above 64MB, you need to install a TAG SRAM upgrade or
use a cache module with an extended TAG SRAM (such as 256KB ASUS CM1
Rev 3.0 with 2 TAG SRAM's) but not both and set this jumper to 512MB. See
page 12 for TAG SRAM upgrade and page 14 for cache module information.

WARNING: If there are DRAM cache chips (MCache) either onboard or on

the SIMM cache module instead of pipelined burst SRAM chips, this jumper
must be set to 64MB. 512MB will make the system unstable. Mcache chips can
only allow cacheable memory up to 64MB. See "Map of Motherboard" on page
4 for L2 cache locations. If the cache module that you install already have an
extended tag, do not install another TAG SRAM into the T AG SRAM Upgrade
Socket.

(Jumpers)

III. INSTALLATION

Cacheable Size JP4

64MB (BSRAM/MCache) [1-2] (Default)
512MB (BSRAM Only) [2-3]

JP4

123

64MB Cacheable (Default)
Burst SRAM or MCache

Cacheable Size (64MB/512MB)

JP4

1

23

512MB Cacheable
Burst SRAM Only

ASUS P/I-P55T2P4 User's Manual 11

III. INSTALLATION

2. System Memory (DRAM & SRAM)

This motherboard supports four 72-pin SIMMs of 4MB, 8MB, 16MB, 32MB, or
64MB to form a memory size between 8MB to 256MB. The DRAM can be either
60ns or 70ns Fast Page Mode (Asymmetric or Symmetric) or EDO. To support
ECC, you must use true (opposed to phantom parity generated by logic chips) 36-bit
parity-type DRAM (e.g. 8 chips + 4 parity chips) in pairs for all modules. Mixing
32-bit non-parity DRAM (e.g. 8 chips) and 36-bit DRAM (e.g. 12 chips) will work
minus the ECC feature.

Install memory in any or all of the banks in any combination as follows:

Bank Memory Module Total Memory
Bank 0 4MB, 8MB, 16MB, 32MB, 64MB x2
SIMM Sockets 1&2 72-pin FPM or EDO SIMM

III. INSTALLATION

(Memory)

Bank 1 4MB, 8MB, 16MB, 32MB, 64MB x2
SIMM Sockets 3&4 72-pin FPM or EDO SIMM

Total System Memory =

IMPORTANT: Memory setup is required in BIOS Chipset Setup "Auto
Configuration" on page 34.

IMPORTANT: Each bank must have the same size memory installed in

pairs. Do not use memory modules with more than 24 chips per module.
Modules with more than 24 chips exceed the design specifications of the
memory subsystem and will be unstable.

TAG SRAM Upgrade:

The purpose of this SRAM is described by "Memory Cacheable Size" jumper . You
must use a standard 5Volt SRAM chip that is 15ns or faster.

Notch

Indention

Insert one 16K8 or
32K8 SRAM chip as
shown by the Top
view with the semi­circle "Indention" on
the same side as the
"Notch."

Top

TAG SRAM Upgrade

Side

WARNING: If the cache module that you install already have an extended tag, do
not install another TAG SRAM into the TAG SRAM Upgrade Socket.

ASUS P/I-P55T2P4 User's Manual12

III. INSTALLATION

DRAM Memory Installation Procedures:

1. The SIMM memory modules will only fit in one orientation as shown because
of a "Plastic Safety Tab" on one end of the SIMM sockets which requires the
"Notched End" of the SIMM memory modules.

1234

Bank0 Bank1

Notched End

72 Pin SIMM DRAM Sockets & Module

2. Press the memory module firmly into place starting from a 45 degree angle
making sure that all the contacts are aligned with the socket.

3. W ith your finger tips, rock the memory module into a vertical position so that
it clicks into place.

Support Clip

Safety Tab (This Side Only)

72 Pin DRAM in SIMM Socket

Mounting Hole

4. The plastic guides should go through the two "Mounting Holes" on the sides
and the "Metal Clips" should snap on the other side.

(DRAM Memory)

III. INSTALLATION

5. T o release the memory module, squeeze both "Metal Clips" outwards and rock
the module out of the "Metal Clips".

ASUS P/I-P55T2P4 User's Manual 13

Static RAM (SRAM) for Level 2 (External) Cache

The motherboard you purchase may have either 0KB, 256KB, or 512KB onboard.
If you have both onboard cache chips (see "Map of Motherboard" for locations) and
a Cache Expansion Slot, then you have 256KB. If you only have onboard cache
chips, then you have 512KB. An "ASUS" or "COAST" cache module can be used
to upgrade the 256KB version to 512KB. The 512KB version cannot be upgraded
any further . If there is no onboard cache, you may install a SIMM cache module of
either 256KB or 512KB.

IMPORTANT: You must set "Total Level 2 Cache Size Setting" jumper on
page 8 when changes are made to your cache size.

III. INSTALLATION

(External Cache)

III. INSTALLATION

42 Pins

38 Pins

Pipelined Burst Cache Module

Insert the module as shown. Because the number of pins are different on either side
of the break, the module will only fit in the orientation as shown.

Compatible Cache Modules for this Motherboard

SIMM Cache Module 256KB to 512KB 0KB to 256/512KB

ASUS CM1 Rev 1.0 No No
ASUS CM1 Rev 1.3 No No
ASUS CM4 Rev 1.5 No No
ASUS CM1 Rev 1.6 Yes No
ASUS CM1 Rev 3.0 Yes Yes
COAST 1.1 No No
COAST 1.2 No No
COAST 1.3 No No
COAST 2.0 Yes Yes
COAST 2.1 Yes Yes
COAST 3.0 Yes Yes
COAST 3.1 Yes Yes

WARNING: If the cache module that you install already have an extended tag, do
not install another TAG SRAM into the TAG SRAM Upgrade Socket.

ASUS P/I-P55T2P4 User's Manual14