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 ASUSTeKCOMPUTER 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 notlimited to the implied warranties or conditions of merchantability or fitness for aparticular purpose. In no event shall ASUS be liable for any loss or profits, loss ofbusiness, 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 ofthe 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. Manualrevisions are released for each board design represented by the digit before andafter 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 pageat http://www.asus.com.tw/ or contact ASUS from the following page.
© Copyright 1997 ASUSTeK COMPUTER INC. All rights reserved.

Product Name:
Manual Revision:
Release Date:II

ASUS P/I-P55T2P4
3.11
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: 886-2-894-3447
Fax:
886-2-894-3449
Email:
info@asus.com.tw

Technical Support:
Fax:
BBS:
Email:
WWW:
Gopher:FTP:

886-2-895-9254
886-2-896-4667
tsd@asus.com.tw
http://www.asus.com.tw/gopher.asus.com.tw
ftp.asus.com.tw/pub/ASUS

ASUS COMPUTER INTERNATIONAL
Marketing Info:
Address: 721 Charcot Avenue, San Jose, CA 95131, USA
Telephone: 1-408-474-0567
Fax:
1-408-474-0568
Email:
info-usa@asus.com.tw

Technical Support:
BBS:
Email:

1-408-474-0555
tsd-usa@asus.com.tw

ASUS COMPUTER GmbH
Marketing Info:
Address: Harkort Str. 25, 40880 Ratingen, BRD, Germany
Telephone: 49-2102-445011
Fax:
49-2102-442066
Email:
info-ger@asus.com.tw

Technical Support:
BBS:
Email:

49-2102-448690
tsd-ger@asus.com.tw

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 .................................................................... 19Power 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
6. BIOS Setup ................................................................................. 29
Load Defaults ....................................................................... 30
Standard CMOS Setup ............................................................... 30

IV

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, andThis 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 toprovide 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 thatinterference will not occur in a particular installation. If this equipment does cause
harmful interference to radio or television reception, which can be determined byturning 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 compliancecould 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
I. INTRODUCTION(Manual / Checklist)

How this manual is organizedThis manual is divided into the following sections:I.
Introduction:
II. Features:
III. Installation:
IV. BIOS Setup:
V. Software:
VI. ASUS SCSI:
VII. ASUS I-A16C:
VIII. DOS/Win3.1x:
IX. Windows 95:

Manual information and checklist
Information and specifications concerning this productInstructions on setting up the motherboard.
BIOS software setup information.
Information on the included support software
Installation of an optional ASUS SCSI cards
Installation of an optional 16-bit Audio card
Audio Software Manual (with ASUS I-A16C bundle)
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.
þ

The ASUS P/I-P55T2P4 motherboardþ

2 serial port ribbon cables attached to a mounting bracketþ

1 parallel ribbon cable with mounting bracket

þ

1 IDE ribbon cableþ

1 floppy ribbon cableþSupport 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 FormþThis 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 Manual1II. FEATURES
Features of the ASUS Motherboard

II. FEATURES(Features)

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.
• Versatile Processor Support: Intel Pentium® 75-233MHz (P55C-MMX™, P54C/
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 Correcting (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 whichallows hardware to communicate within a standard protocol creating a higher
level of compatibility (see section V).
• L2 Cache: Provides the option of 0KB upgradeable to 256KB or 512KB, onboard 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 withPCI Slot 4 for an optional high-performance expansion card which includes twofunctions in one easy-to-install card. (For revision compatibility information, please refer to page 18.)
• Super Multi-I/O: Provides two high-speed UART compatible serial ports andone parallel port with EPP and ECP capabilities. UART2 can also be directedfrom COM2 to the Infrared Module for wireless connections. Two floppy drivesof 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 isalso supported.

2

ASUS P/I-P55T2P4 User’s ManualII. FEATURES••

PCI Bus Master IDE Controller: Comes with an onboard PCI Bus MasterIDE controller with two connectors that supports four IDE devices in two channels, provides faster data transfer rates, and supports Enhanced IDE devices
such as Tape 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 anoptional 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

II. FEATURES(Parts of Board)•

Parallel & Serial Ports

3 ISA Slots
Programmable
Flash ROM
3 PCI Slots

Super Multi-I/O
Onboard Floppy& IDE Connect.

PCI 4 or ASUSMediaBus 2.0(4) 72-pin SIMM
Sockets
Upgradeable
TAG SRAM
Self-Powered
RealTime ClockIntel's 430HX
PCIsetCPU ZIF Socket 7
L2 Upgrade
Cache
Expansion Slot
Onboard 256KB/
512KB Pipelined
Burst L2 Cache

ASUS P/I-P55T2P4 User’s Manual3III. INSTALLATION
Map of the ASUS Motherboard
Keyboard

PS/2 Mouse

JP2
Boot Block Write (Dis/En)
Universal Serial Bus(Reserved for future use)

ISA Slot 1

COM 2

Serial (COM) Ports
Parallel (Printer) Port

Multi-I/O(En/Dis)

MULTI I/O
ChipsetSIMM Socket 4 (Bank 1)

P8

SIMM Socket 3 (Bank 1)

P9

Board Power Input

Secondary IDE

Primary IDE

Floppy Drives

SIMM Socket 2 (Bank 0)

JP1

SIMM Socket 1 (Bank 0)

PCI Slot 1

PCI Slot 2

PCI Slot 3

PCI Slot 4

ISA Slot 2

III. INSTALLATION(Map of Board)

ISA Slot 3

COM 1

MediaBus 2.0
Cacheable
64/512MB

CMOS Operation/Clear

JP11
JP12

Case Connector

4

Freq Ratio

IDE LED

Infrared Conn.

12V Fan PowerCPU VCore
JP20

JP17

CPU ZIF Socket 7

TAG SRAM Upgrade

JP8
JP9
JP10

BUS Freq

Pipelined Burst Level 2 Cache Expansion Slot

JP4

JP7

JP5

L2 Cache Size (256/512)

256/512KB onboard L2 Cache

Voltage (STD/VRE)

ASUS P/I-P55T2P4 User’s ManualIII. INSTALLATION
1) JP1
2) JP2
3) JP54) JP75) JP176) JP20
7) JP8, JP9,JP10
8) JP11, JP129) JP4

p. 7
p. 7
p. 8
p. 8
p. 9
p. 9
p. 10
p. 10
p. 11

Multi-I/O Selection (Enable/Disable)
Flash ROM Boot Block Program (Disable/Enable)
Total Level 2 Cache Size Setting (256/512KB)
Real Time Clock RAM (Operation/Clear Data)
Single Power Plane CPU Voltage Selection
Dual Power Plane CPU Voltage Selection
CPU External Clock (BUS) Frequency Selection
CPU:BUS Frequency Ratio
Memory Cacheable Size (64MB / 512MB)

p. 12
p. 12
p. 14
p. 15
p. 16
p. 16
p. 18

DRAM Memory Expansion Sockets
Upgrade socket for TAG SRAM
Socket for Pipelined Burst SRAM Cache Module
Socket for Central Processing Unit (CPU)16-bit ISA Bus Expansion Slots
32-bit PCI Bus Expansion Slots
32-bit PCI Bus Slot and MediaBus

p. 19
p. 19
p. 20
p. 20
p. 21
p. 21
p. 22
p. 22
p. 23
p. 23
p. 23
p. 23
p. 23
p. 24
p. 24

Keyboard Connector (5-pin Female)
PS/2 Mouse Connector (6-pin Block)
Parallel Port Connector (26-pin Block)
Serial Port COM1 & COM2 (10-pin Blocks)
Floppy Drive Connector (34-pin Block)Motherboard Power Connector (12-pin Block)Primary/Secondary IDE Connectors (40-pin Blocks)
IDE LED Activity Light
Turbo LED/Power LED (2-pins)
SMI Switch Lead (2-pins)
Reset Switch Lead (2-pins)
Keyboard Lock Switch Lead (5-pins)
Speaker Connector (4-pins)
CPU 12V Cooling Fan Connector
Infrared Port Module Connector

III. INSTALLATION(Map of Board)

Jumpers

Expansion Slots
1) SIMM Sockets
2) TAG SRAM
3) Cache Expansion4) CPU ZIF Socket 75) ISA Slots 1, 2, 36) PCI Slots 1, 2, 37) PCI 4 / MediaBus

Connectors
1) Keyboard2) PS/2 Mouse
3) Parallel Port
4) Serial Port
5) Floppy Drive
6) Power Input
7) Primary/Second. IDE8) IDE LED
9) Turbo/Power (CON1)
10) SMI Switch (CON1)
11) Reset Switch (CON1)
12) Key Lock (CON1)
13) Speaker (CON1)
14) FAN15) IR CON

ASUS P/I-P55T2P4 User's Manual5III. INSTALLATION
Installation Steps
Before using your computer, you must complete the following steps:
1.
2.
3.
4.
5.
6.

Set Jumpers on the Motherboard
Install DRAM and SRAM Modules
Install the Central Processing Unit (CPU)Install Expansion Cards
Connect Ribbon Cables, Cabinet Wires, and Power Supply
Setup the BIOS Software

1. Jumpers
III. INSTALLATION(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 [----],[1-2], [2-3] for no connection, connect pins 1&2, and connect pins 2&3 respecor on the leftwhen
tively. Pin 1 for our motherboards is always on top
holding the motherboard with the keyboard connector away from yourself. A "1" iswritten besides pin 1 on jumpers with three pins. The jumpers will also be showngraphically such as
to connect pins 1&2 andto connect pins 2&3.
Jumpers with two pins will be shown as
for Short (On) andfor Open(Off). For manufacturing simplicity, the jumpers may be sharing pins from othergroups. Use the diagrams in this manual instead of following the pin layout on theboard. 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.
Pin 1

Pin 1

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 withthe component whenever the components are separated from the system.

6

ASUS P/I-P55T2P4 User's Manual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.
JP1[1-2] (Default)
[2-3]
JP1
1
2
3

JP1
1
2
3

Enable (Default)

Disabled

III. INSTALLATION(Jumpers)

Selections
EnableDisableMulti I/O Setting (Enable / Disable)

2. Flash ROM Boot Block Programming (JP2)This sets the operation mode of the boot block area of the BIOS Flash ROM toallow programming in the Enabled position.
Programming
Disabled
EnabledJP2[1-2] (Default)
[2-3]
JP2

JP2
1 2 3
Disabled (Default)

1 2 3
EnabledBoot Block Programming (Disable / Enable)

ASUS P/I-P55T2P4 User's Manual7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 bothonboard 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 cachecombination, set the following jumpers according to the total amount of L2
cache that is present onboard and installed as a module.
Selections
256KB
512KB

JP5
[1-2]
[2-3]

III. INSTALLATION(Jumpers)

JP5
1
2
3

JP5
1
2
3

256KB

512KB

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

4. Real Time Clock (RTC) RAM (JP7)This clears the user-entered information stored in the CMOS RAM of the RealTime 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

JP7

Operation (Default)

Clear Data

RTC RAM (Operation / Clear Data)

8

ASUS P/I-P55T2P4 User's Manual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 DualPower Planes at the same time.
WARNING: Incorrect setting can damage your CPU. If you are notexactly 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.
Voltage
STD (3.4 Volts)
VRE (3.5 Volts)

JP17[1-2] (Default)
[2-3]

JP17

JP17

1 2 3
P54C/CS/K5(STD 3.4V) (Default)

1 2 3
P54C/CS/K5/6x86(VRE 3.5 Volts)

III. INSTALLATION(Jumpers)

CPU Manufacturer CPU TypeIntel/AMD
P54C/CS/K5
Intel/AMD/IBM/Cyrix P54C/CS/K5/6x86

Voltage Regulator Output Selection (STD / VRE)

6. Dual Power Plane CPU Voltage Regulator Selection (JP20)
These jumpers set the voltage supplied to dual power plane CPU's.
CPU Manufacturer
AMD
AMDIntel/IBM/Cyrix(Reserved)(Reserved)

CPU Type
K6-PR233
K6-PR166,200
P55C/6x86MX(Reserved)(Reserved)

Voltage
3.2 Volts
2.9 Volts
2.8 Volts
2.7 Volts
2.5 Volts

JP20[9-10][7-8][5-6] (Default)
[3-4]
[1-2]

[9-10]
JP20

[7-8]
JP20

[5-6]
JP20

K6-PR233(3.2 Volts)

K6-PR166,200(2.9 Volts)

P55C/6x86MX(2.8V) (Default)

CPU Vcore Voltage Selection

ASUS P/I-P55T2P4 User's Manual9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 Clocktimes 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.

1
2
3

1
2
3

1
2
3

50MHz
55MHz
60MHz
66MHz
CPU External Clock (BUS) Frequency Selection

1
2
3
75MHz

JP11
JP12

JP11
JP12

JP11
JP12

JP11
JP12

1
2
3

1
2
3

1
2
3

1.5x(3/2) 2.0x(2/1)
P54C/K5
P55C/K6/MX 3.5X(7/2) 2.0x(2/1)
IBM/Cyrix 6x86 3.0x(3/1) 2.0x(2/1)
CPU : BUS Frequency Ratio

2.5x(5/2)
2.5x(5/2)
1.0x(1/1)

3.0x(3/1)
3.0x(3/1)
4.0x(4/1)

III. INSTALLATION(Jumpers)123Complete Names:Intel Pentium P54C, P55C-MMX
AMD K5, K6
IBM/Cyrix 6x86, 6x86MX

JP8
JP9
JP10

JP8
JP9
JP10

JP8
JP9
JP10

JP8
JP9
JP10

JP8
JP9
JP10
1
2
3

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

Freq.
233MHz200MHz166MHz150MHz133MHz120MHz
100MHz
90MHz
75MHz

Ratio
3.5x
3.0x
2.5x
2.5x
2.0x
2.0x
1.5x
1.5x
1.5x

B. Freq.
66MHz
66MHz
66MHz
60MHz
66MHz
60MHz
66MHz
60MHz
50MHz

(BUS Freq.)
JP10 JP9 JP8[2-3] [1-2] [2-3][2-3] [1-2] [2-3][2-3] [1-2] [2-3][1-2] [2-3] [2-3][2-3] [1-2] [2-3][1-2] [2-3] [2-3][2-3] [1-2] [2-3][1-2] [2-3] [2-3][2-3] [2-3] [2-3](Freq. Ratio)
JP12 JP11[1-2] [1-2][2-3] [1-2][2-3] [2-3][2-3] [2-3][1-2] [2-3][1-2] [2-3][1-2] [1-2][1-2] [1-2][1-2] [1-2]

AMD-K6-PR233
AMD-K6-PR200
AMD-K6-PR166

233MHz200MHz166MHz

3.5x
3.0x
2.5x

66MHz
66MHz
66MHz

[2-3] [1-2] [2-3][2-3] [1-2] [2-3][2-3] [1-2] [2-3][1-2] [1-2][2-3] [1-2][2-3] [2-3]

AMD-K5-PR133/100
AMD-K5-PR120/90
AMD-K5-PR75

100MHz
90MHz
75MHz

1.5x
1.5x
1.5x

66MHz
60MHz
50MHz

[2-3] [1-2] [2-3][1-2] [2-3] [2-3][2-3] [2-3] [2-3][1-2] [1-2][1-2] [1-2][1-2] [1-2]

IBM/Cyrix 6x86MX-PR233
IBM/Cyrix 6x86MX-PR200
IBM/Cyrix 6x86MX-PR166

200MHz166MHz150MHz

3.0x
2.5x
2.5x

66MHz
66MHz
60MHz

[2-3] [1-2] [2-3][2-3] [1-2] [2-3][1-2] [2-3] [2-3][2-3] [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.

10

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATION
Compatible Cyrix CPU Identification
The only Cyrix CPU that is supported on this motherboard islabeled 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.

III. INSTALLATION(Jumpers)

9. Memory Cacheable Size (JP4)The default of 64MB uses only the onboard TAG 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 oruse 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 canonly 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 TAG SRAM Upgrade
Socket.
Cacheable Size
64MB (BSRAM/MCache)
512MB (BSRAM Only)

JP4[1-2] (Default)
[2-3]

JP4

JP4
1 2 3
64MB Cacheable (Default)
Burst SRAM or MCache

1 2 3
512MB Cacheable
Burst SRAM Only

Cacheable Size (64MB/512MB)

ASUS P/I-P55T2P4 User's Manual11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:

III. INSTALLATION(Memory)

Bank
Bank 0SIMM Sockets 1&2

Memory Module
4MB, 8MB, 16MB, 32MB, 64MB
72-pin FPM or EDO SIMM

Total Memory

Bank 1SIMM Sockets 3&4

4MB, 8MB, 16MB, 32MB, 64MB
72-pin FPM or EDO SIMM

x2

Total System Memory=

x2

IMPORTANT: Memory setup is required in BIOS Chipset Setup "AutoConfiguration" on page 34.
IMPORTANT: Each bank must have the same size memory installed inpairs. Do not use memory modules with more than 24 chips per module.
Modules with more than 24 chips exceed the design specifications of thememory 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 Topview with the semicircle "Indention" on
the same side as the"Notch."Top
Side
TAG SRAM Upgrade

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.

12

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATIONDRAM Memory Installation Procedures:
1. The SIMM memory modules will only fit in one orientation as shown becauseof a "Plastic Safety Tab" on one end of the SIMM sockets which requires the"Notched End" of the SIMM memory modules.

Bank0 Bank1

III. INSTALLATION(DRAM Memory)

1 2 3 4

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. With your finger tips, rock the memory module into a vertical position so thatit clicks into place.
Support Clip

72 Pin DRAM in SIMM Socket

Safety Tab (This Side Only)

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.
5. To release the memory module, squeeze both "Metal Clips" outwards and rockthe module out of the "Metal Clips".

ASUS P/I-P55T2P4 User's Manual13III. INSTALLATION
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) anda Cache Expansion Slot, then you have 256KB. If you only have onboard cachechips, 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 ofeither 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.

42 Pins

III. INSTALLATION(External Cache)

38 Pins

Pipelined Burst Cache Module

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

Compatible Cache Modules for this Motherboard
SIMM Cache Module
ASUS CM1 Rev 1.0
ASUS CM1 Rev 1.3
ASUS CM4 Rev 1.5
ASUS CM1 Rev 1.6
ASUS CM1 Rev 3.0
COAST 1.1
COAST 1.2
COAST 1.3
COAST 2.0
COAST 2.1
COAST 3.0
COAST 3.1

256KB to 512KB
No
No
No
Yes
Yes
No
No
No
Yes
Yes
Yes
Yes

0KB to 256/512KB
No
No
No
No
Yes
No
No
No
Yes
Yes
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.
14

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATION
3. Central Processing Unit (CPU)The motherboard provides a 321-pin ZIF Socket 7 that is backwards
compatible with ZIF Socket 5 processors. The CPU that came with the motherboard
should have a fan attached to it to prevent overheating. If this is not the case thenpurchase a fan before you turn on your system. Apply thermal jelly to the CPU top
and then install the fan onto the CPU.
WARNING: Without a fan, the CPU can overheat and cause damage to both
the CPU and the motherboard. (See page 24 "CPU Cooling Fan Connector.)

III. INSTALLATION(CPU)

To install a CPU, first turn off your system and remove its cover. Locate the ZIF
socket and open it by first pulling the lever sideways away from the socket then
upwards to a 90-degree right angle. Insert the CPU with the correct orientation asshown. Use the notched corner of the CPU with the white dot as your guide. The
white dot should point towards the end the of the lever. Notice that there is a blankarea where one hole is missing from that corner of the square array of pin holes anda "1" printed on the motherboard next to that corner. Because the CPU has a corner
pin for three of the four corners, the CPU will only fit in the one orientation asshown. The picture is for reference only; you should have a CPU fan that will cover
the face of the CPU. With the added weight of the CPU fan, no force is required toinsert the CPU. Once completely inserted, hold down on the fan and close thesocket's lever.
IMPORTANT: You must set jumpers for "CPU to BUS Frequency Ratio" andjumpers for "BUS Frequency Selection" on page 10 depending on the CPU
that you install.

Lever
Lock

1

Blank

White Dot

ASUS P/I-P55T2P4 User's Manual

1

ZIF Socket 7 with Pentium Processor

15

III. INSTALLATION
4. Expansion Cards
WARNING: Make sure that you unplug your power supply when adding or
removing expansion cards or other system components.
Failure to do so may cause severe damage to both your motherboard and expansion cards.
First read your expansion card documentation on any hardware andsoftware settings that may be required to setup your specific card.
NOTE: PCI Slot 4 has a MediaBus extension 2.0 (see page 18) which allows theinstallation of a PCI card or a MediaBus card (optional multifunctional card) but not
both.
III. INSTALLATION(Expansion Cards)

Expansion Card Installation Procedure:
1.
2.
3.
4.
5.
6.
7.
8.
9.

Read the documentation for your expansion card.
Set any necessary jumpers on your expansion card.
Remove your computer system's cover.
Remove the bracket on the slot you intend to use. Keep the bracket for possible future use.
Carefully align the card’s connectors and press firmly.
Secure the card on the slot with the screw you removed in step 4.
Replace the computer system's cover.
Setup the BIOS if necessary (such as "IRQ xx Used By ISA: Yes" in PNP AND
PCI SETUP)
Install the necessary software drivers for your expansion card.

Assigning IRQs for Expansion Cards
Some expansion cards need to use an IRQ to operate. Generally an IRQ must be
exclusively assigned to one use. In an standard design there are 16 IRQs available
but most of them are already in use by parts of the system which leaves 6 free for
expansion cards.

16

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATION
Both ISA and PCI expansion cards may need to use IRQs. System IRQs are available to cards installed in the ISA expansion bus first, and any
remaining IRQs are then used by PCI cards. Currently, there are two types of ISA
cards. The original ISA expansion card design, now referred to as “Legacy” ISA
cards, requires that you configure the card’s jumpers manually and then install it inany available slot on the ISA bus. You may use Microsoft's Diagnostic (MSD.EXE)
utility included in the Windows directory to see a map of your used and free IRQs.
For Windows 95 users, the "Control Panel" icon in "My Computer," contains a "System" icon which gives you a "Device Manager" tab. Double clicking on a specificdevice give you "Resources" tab which shows the Interrupt number and address.
Make sure that no two devices use the same IRQs or your computer will experienceproblems when those two devices are in use at the same time.

III. INSTALLATION(DMA Channels)

To simplify this process this motherboard has complied with the Plug and Play (PNP)
specification which was developed to allow automatic system configuration whenever a PNP-compliant card is added to the system. For PNP cards, IRQs are assigned automatically from those available.
If the system has both Legacy and PNP ISA cards installed, IRQs are
assigned to PNP cards from those not used by Legacy cards. The PCI and PNP
configuration of the BIOS setup utility can be used to indicate which IRQs are being
used by Legacy cards. For older Legacy cards that does not work with the BIOS,
you can contact your vendor for an ISA Configuration Utility.
An IRQ number is automatically assigned to PCI expansion cards after those usedby Legacy and PNP ISA cards. In the PCI bus design, the BIOS automaticallyassigns an IRQ to a PCI slot that has a card in it that requires an IRQ. To install a
PCI card, you need to set something called the INT (interrupt) assignment. Since all
the PCI slots on this motherboard use an INTA #, be sure that the jumpers on your
PCI cards are set to INT A.

Assigning DMA Channels for ISA Cards
Some ISA cards, both Legacy and PNP may also need to use a DMA (Direct Memory
Access) channel. DMA assignments for this motherboard are handled the same way
as the IRQ assignment process described above. You can select a DMA channel in
the PCI and PNP configuration section of the BIOS Setup utility.
IMPORTANT: Choose "Yes" for those IRQ's and DMA's you wish to reservefor Legacy (Non-PnP) ISA expansion cards in “IRQ xx Used By ISA” and “DMAx Used By ISA” of the PNP and PCI Setup in the BIOS SOFTWARE section,otherwise conflicts may occur.

ASUS P/I-P55T2P4 User's Manual17III. INSTALLATION
ASUS MediaBus CardMediaBus allows a cost-efficient solution to a complete multimedia system. The
advantages of using one add-on card is to reduce the slot requirements and compatibility problems in order to maximize the Plug and Play advantages. The add-on
card inserts into the shared PCI 4 / MediaBus 2.0 Slot.
NOTE: This motherboard uses MediaBus Rev. 2.0. The previous MediaBus
cards designed for MediaBus Rev. 1.2 will not fit into the MediaBus Rev 2.0
that is on this motherboard.

III. INSTALLATION(MediaBus Card)

The difference between Rev. 1.2 and Rev. 2.0 is that the later revision has 72 pins
instead of 68 so it does not have to use any PCI slot signals reserved for PCI cards,
therefore the motherboard's PCI Slot 4 can meet standard specifications. The gap
between the MediaBus extension and the PCI Slot 4 has been increased from 0.32"
to 0.40" in order to prevent Rev. 1.2 MediaBus cards from being installed into thenew motherboards and vice versa.

The following are MediaBus cards designed for MediaBus 2.0 that can be used on
this motherboard:• PCI-AS2940UW• PCI-AV264CT-N• PCI-AV264VT• PCI-AV264GT• PCI-AV264GT/Plus

Ultra Fast/Wide SCSI & Audio MediaBus Card
PCI Audio & Video MediaBus Card
PCI Audio & Video MediaBus Card
PCI Audio & Video MediaBus Card
PCI Audio & Video MediaBus Card

The following are MediaBus cards designed for MediaBus 1.2 and therefore
cannot be used on this motherboard:• PCI-AS7870• PCI-AV264CT• PCI-AV868

Fast/Wide SCSI & Audio MediaBus Card
PCI Audio & Video MediaBus Card
PCI Audio & Video MediaBus Card

* All the above Audio features Creative Technology, Ltd.
* All the above Video features ATI, Inc. (AV868 Video features S3, Inc.)* All the above SCSI features Adaptec, Inc.

18

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATION
5. External Connectors
WARNING: Some pins are used for connectors or power sources. These areclearly separated from jumpers in "Map of the Motherboard" on page 4. Placing jumper caps over these will cause damage to your motherboard.
IMPORTANT: Ribbon cables should always be connected with the red stripeon the Pin 1 side of the connector. The four corners of theconnectors are labeled on the motherboard. Pin 1 is the side closest to thepower connector on hard drives and floppy drives. IDE ribbon cable must be
less than 18in. (46cm), with the second drive connector no more than 6in. (15cm)
from the first connector.

III. INSTALLATION(Connectors)

1. Keyboard Connector (5-pin female)This connection is for a standard IBM-compatible keyboard. May also be
known as a 101 enhanced keyboard.

Keyboard Connector (5-pin female)Connector Plug from Keyboard

2. PS/2 Mouse Connector (6-pin block)If you are using a PS/2 mouse, you must purchase an optional PS/2 mouse set
which connects to the 6 pin block and mounts to an open slot on your computer'scase. The system will direct IRQ12 to the PS/2 mouse if one is detected. If notdetected, expansion cards can use IRQ12. See PS/2 Mouse Control in BIOSFEATURES SETUP.
1 234
5
8
1 234
5

8

1: GND
2: DATA
3: NC
4: VCC
5: CLK
8: NC

PS/2 Mouse Module Connector

ASUS P/I-P55T2P4 User's Manual19III. INSTALLATION
3. Parallel Printer Connector (26 Pin Block)Connection for the included parallel port ribbon cable with mounting bracket.
Connect the ribbon cable to this connection and mount the bracket to the caseon an open slot. It will then be available for a parallel printer cable. Note:
Serial printers must be connected to the serial port. You can enable the parallel
port and choose the IRQ through BIOS Setup on page 36 "Onboard ParallelPort." (Pin 26 is removed to prevent inserting in the wrong orientation
when using ribbon cables with pin 26 plugged).

Pin 1

III. INSTALLATION(Connectors)

Onboard Parallel (Printer) Connector

4. Serial Port COM1 and COM2 Connectors (Two 10-pin blocks)
These connectors support the provided serial port ribbon cables with mounting
bracket. Connect the ribbon cables to these connectors and mount the bracket
to the case on an open slot. The two serial ports on the mounting bracket willthen be used for pointing devices or other serial devices. See page 35 for
BIOS configuration of "Onboard Serial Port". (Pin 10 is removed to prevent
inserting in the wrong orientation when using ribbon cables with pin 10
plugged).
COM 1

COM 2

Pin 1

Pin 1

Onboard Serial Port Connectors

20

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATION
5. Floppy Drive Connector (34-pin block )This connector supports the provided floppy drive ribbon cable. After connecting the single end to the board, connect the two plugs on the other end to
the floppy drives. (Pin 5 is removed to prevent inserting in the wrong orientation when using ribbon cables with pin 5 plugged).
Pin 1

III. INSTALLATION(Connectors)

Floppy Drive Connector

6. Power Connector (12-pin block)This connector connects to a standard 5 Volt power supply. To connect theleads from the power supply, ensure first that the power supply is not plugged.
Most power supplies provide two plugs (P8 and P9), each containing six wires,two of which are black. Orient the connectors so that the black wires arelocated in the middle.
Using a slight angle, align the plastic guide pins on the lead to their receptacles
on the connector. Once aligned, press the lead onto the connector until thelead locks into place.

-5V

GND

PG
Power Connector
on Motherboard

+5V

P8

-12V
+12V

RED
RED
RED
WHT
BLK
BLK
BLK
BLK
BLU
YLW
RED
ORG

P9

+5V

Power Plugs fromPower Supply

ASUS P/I-P55T2P4 User's Manual21III. INSTALLATION
7. Primary / Secondary IDE Connectors (Two 40-pin Block)
These connectors support the provided IDE hard disk ribbon cable.
After connecting the single end to the board, connect the two plugs at the otherend to your hard disk(s). If you install two hard disks, you must configure thesecond drive to Slave mode by setting its jumper accordingly. Please refer tothe documentation of your hard disk for the jumper settings. You may also
configure two hard disks to be both Masters using one ribbon cable on the
primary IDE connector and another ribbon cable on the secondary IDE connector. BIOS now supports SCSI device or IDE CD-ROM bootup (see "HDD
Sequence SCSI/IDE First" & "Boot Sequence" in the BIOS FEATURES SETUPof the BIOS software) (Pin 20 is removed to prevent inserting in the wrong
orientation when using ribbon cables with pin 20 plugged).
Pin 1

III. INSTALLATION(Connectors)

Secondary IDE Connector
Primary IDE Connector

8. IDE Activity LED (IDE LED)
This connector connects to the hard disk activity indicator light on the systemcabinet.

IDE LED+IDE Activity LED

22

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATION
9. Turbo LED Lead (CON1)
The motherboard's turbo function is always on. The turbo LED connection islabeled here but the LED will remain constantly lit while the system power ison. You may wish to connect the Power LED from the system case to this lead.
See the figure below.

III. INSTALLATION(Connectors)

10. SMI Suspend Switch Lead (CON1)
This allows the user to manually place the system into a suspend mode or "Green"mode where system activity will be instantly decreased to save electricity andexpand the life of certain components when the system is not in use. This 2-pin
connector (see the figure below) connects to the case-mounted suspend switch.
If you do not have a switch for the connector, you may use the "Turbo Switch"since it does not have a function. SMI is activated when it detects a short to open
moment and therefore leaving it shorted will not cause any problems. May require one or two pushes depending on the position of the switch. Wake-up can
be controlled by settings in the BIOS but the keyboard will always allow wakeup (the SMI lead cannot wake-up the system). If you want to use this connector,"Suspend Switch" in the POWER MANAGEMENT SETUP of the BIOS software should be on the default setting of Enable.
11. Reset Switch Lead (CON1)
This 2-pin connector connects to the case-mounted reset switch for rebooting
your computer without having to turn off your power switch This is a preferred method of rebooting in order to prolong the life of the system's power
supply. See the figure below.
12. Keyboard Lock Switch Lead & System Power LED (CON1)
This 5-pin connector connects to the case-mounted keyboard lock switch forlocking the keyboard and also to connect the system power LED. The system
power LED lights when the system is powered on. See the figure below.
13. Speaker Connector (CON1)
This 4-pin connector connects to the case-mounted speaker.
Turbo orPower LED
SMI Lead

Reset SW

GND

+5V
NC
GND
LOCK
GND

GND

+5V
GND
GND
SPKR

+5V
GND

Power LED &Keyboard Lock
SpeakerConnector

System Case Connections

ASUS P/I-P55T2P4 User's Manual23III. INSTALLATION
14. CPU Cooling Fan Connector (FAN)
This connector supports a CPU cooling fan of 500mAMP (6WATT) or less.
Orientate the fan so that the heat sink fins allow airflow to go across the onboard heat sink(s) instead of the expansion slots. Depending on the fan manufacturer, the wiring and plug may be different. The red wire should be positive, while the black should be ground. Connect the fan's plug to the board
taking into consideration the polarity of the this connector.
WARNING: The CPU and/or motherboard will overheat if there is no airflow
across the CPU and onboard heatsinks. Damage may occur to the motherboard and/or the CPU fan if these pins are incorrectly used. These are not
jumpers, do not place jumper caps over these pins.

III. INSTALLATION(Connectors)

Air Flow

Air Flow
FAN
GND

+12V

CPU Fan Power

15. IrDA-Compliant Infrared Module Connector (IR)This connector supports the optional wireless transmitting andreceiving infrared module. This module mounts to a small opening on systemcases that support this feature. You must also configure the setting through
BIOS setup on page 36 "UART2 Use Infrared" to select whether UART2 isdirected for use with COM2 or IrDA. Use the five pins as shown on the Back
View and connect a ribbon cable from the module to the motherboard according to the pin definitions.

NC
GND

+5V

Back View

IRRX
IRTX

Front View

+5V
NC

IRTX
GND
IRRX
Infrared Module Connector

24

ASUS P/I-P55T2P4 User's ManualIII. INSTALLATIONPower Connection Procedures
1. After all jumpers and connections are made, close the system case cover.
2. Make sure that all switches are in the off position as marked by.

3. Connect the power supply cord into the power supply located on the back ofyour system case as instructed by your system user's manual.
4. Connect all power cords into a power strip that is equipped by a surge protector.
5. You may then turn on your devices in the following order:
a. Your monitor
b. External SCSI devices (starting with the last device on the chain)c. Your system power

III. INSTALLATION(Power Connections)6. The power LED on the front panel of the system case will light and the monitor
LED as well. The system will then run power-on tests. While the tests are
running, additional messages will appear on the screen. If you do not see anything within 30 seconds from the time you turn on the power, the system may
have failed a power-on test. Recheck your jumper settings and connections orcall your authorized dealer for assistance.
7. During power-on, hold down the <Delete> key to enter BIOS setup. Follow thenext section "BIOS SOFTWARE" for instructions.

ASUS P/I-P55T2P4 User’s Manual25

IV. BIOS SOFTWARE
Support Software
FILELIST.TXT - View this file to see the files included in the support software.
PFLASH.EXE - This is the Flash Memory Writer utility that updates the BIOS byuploading a new BIOS file to the programmable flash ROM chip on the motherboard. To determine the BIOS version, check the last four numbers of the code
displayed on the upper left-hand corner of your screen during bootup. Larger numbers represent a newer BIOS file.
NOTE: A binary BIOS file is no longer included with the support software.
Save the motherboard's BIOS file to a floppy diskette as soon as your system isoperational. See "Flash Memory Writer Utility" in this section to “SaveCurrent BIOS to File.”

Flash Memory Writer Utility
ASUSTeK PNP BIOS
FLASH MEMORY WRITER V1.5
Copyright (C) 1995, ASUSTeK COMPUTER Inc.
Flash Type -- SST 29EE010
Current BIOS Revision: #401A0-xxxx
Choose one of the following:

IV. BIOS(Flash Memory Writer)

1. Save Current BIOS To File
2. Update BIOS Main Block From File
3. Advanced Features
Enter Choice: [1]Press ESC To Exit

xxxx denotes the current BIOS version stored in the Flash EPROM

IMPORTANT: Flash Type may also be "INTEL 28F001BXT." If "unknown"
is shown after "Flash type --," then this ROM chip is not programmable or notsupported with the PnP BIOS and therefore cannot be programmed by theFlash Memory Writer.

Main Menu
1. Save Current BIOS to File (Perform as soon as system is operational)
This option allows you to copy the contents of the Flash memory chip onto a diskette. This gives you a backup copy of the original motherboard BIOS in case youneed to re-install it.
Create a bootable system floppy diskette by typing [FORMAT A:/S] from the
DOS environment without creating "AUTOEXEC.BAT" and "CONFIG.SYS"
files, then save the PFLASH.EXE and the BIOS to the floppy diskette.

26

ASUS P/I-P55T2P4 User’s ManualIV. BIOS SOFTWARE
2. Update BIOS Main Block from File
This option updates the BIOS from a file on the disk. This can either be a new fileor a backup file created by the “Save Current BIOS to File” option. This will not
update the Boot Block if the Boot Block is different. You will be prompted with thefollowing if advanced features if necessary.
Boot Block of New BIOS is different from old one !!!
Please Use 'Advanced Feature' to flash whole bios !!!
3. Advanced Features
Selecting this option brings up the Advanced Features screen for clearing the PnP
configuration record and updating the motherboard BIOS.

Advanced Features Menu
Advanced Features

Flash Type -- SST 29EE010
Current BIOS Revision: #401A0-xxxx
Choose one of the following:
1. Clear PNP ESCD Parameter Block

IV. BIOS(Flash Memory Writer)

2. Update BIOS Including Boot Block and ESCDEnter Choice: [2]Press ESC To Exit

xxxx denotes the current BIOS version stored in the Flash EPROM

1. Clear PNP ESCD Parameter BlockThis option erases the Plug-and-Play (PnP) configuration record.
2. Update BIOS Including Boot Block and ESCDThis option updates the Boot Block, the motherboard BIOS and the PnP ESCD
Parameter Block from a new BIOS file.
NOTE: "Update BIOS Main Block from File" and "Update BIOS Including Boot
Block and ESCD" requires that the system is running in real mode. This utility will
not operate if the system is under protected mode or virtual mode. You should bootfrom a system floppy diskette without "AUTOEXEC.BAT" and "CONFIG.SYS" files.

ASUS P/I-P55T2P4 User’s Manual27

IV. BIOS SOFTWARE
Updating your Motherboard's BIOS
1. Download an updated BIOS file from Bulletin Board Services (BBS) or theinternet (WWW) and save to the diskette you created in step 1 of the Main
Menu. See ASUS CONTACT INFORMATION on page II.
2. Turn off your computer and open the system cabinet to Enable "Boot Block
Programming" jumper as shown in section III.
2. Boot from the floppy diskette you created in step 1 of the main menu.
3. At the "A:\" prompt, type: PFLASH <Enter>
4. Enter "2" from the Main Menu or "2" from the Advanced Features Menu.
5. The program displays a second screen prompting you for the name of the BIOS
file. Type in the complete name of the file, including the file name extension,and then press the <Enter> key. The utility then uploads the BIOS file fromdisk. The following message will appear:
DO NOT TURN OFF THE SYSTEM IF THERE IS A PROBLEM!

IV. BIOS(Flash Memory Writer)

If you encounter problems while downloading the new BIOS, DO NOT turn off
your system since this might prevent your system frombooting up. Just repeat the process, and if the problem still persists, upload theoriginal BIOS file you saved to disk in step 1 of the Main Menu.
WARNING: If the Flash Memory Writer utility was not able to successfully
download a complete BIOS file, your system may not be able to boot up. If
this happens, your system will require service from your vendor.
6. After successfully downloading the new BIOS file, exit the Flash Memory Writerutility and then turn off your system. Set the jumper back to its default settingof Programming “Disabled.”
7. Turn on your computer and hold down <delete> to enter BIOS setup. You mustselect "Setup Default" to affect the new BIOS, then you may set other items
from the Main Menu.

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6. BIOS Setup
The motherboard supports two programmable Flash ROM chips: 5 Volt and 12
Volt. Either of these memory chips can be updated when BIOS upgrades are released. Use the Flash Memory Writer utility to download the new BIOS file into the
ROM chip as described in detail in this section.
All computer motherboards provide a Setup utility program for specifying the system configuration and settings. If your motherboard came in a computer system, theproper configuration entries may have already been made. If so, invoke the Setup
utility, as described later, and take note of the configuration settings for future reference; in particular, the hard disk specifications.
If you are installing the motherboard, reconfiguring your system or you receive a
Run Setup message, you will need to enter new setup information. This section
describes how to configure your system using this utility.

IV. BIOS(BIOS Setup)

The BIOS ROM of the system stores the Setup utility. When you turn on the computer, the system provides you with the opportunity to run this program. This appears during the Power-On Self Test (POST). Press <Delete> to call up the Setup
utility. If you are a little bit late pressing the mentioned key(s), POST will continue
with its test routines, thus preventing you from calling up Setup. If you still need tocall Setup, reset the system by pressing <Ctrl> + <Alt> + <Delete>, or by pressing
the Reset button on the system case. You can also restart by turning the system off
and then back on again. But do so only if the first two methods fail.ß
When you invoke Setup, the CMOS SETUP UTILITY main program screen willappear with the following options:

ASUS P/I-P55T2P4 User’s Manual29IV. BIOS SOFTWARE
Load Defaults
The “Load BIOS Defaults” option loads the minimized settings for troubleshooting.
“Load Setup Defaults”, on the other hand, is for loading optimized defaults forregular use. Choosing defaults at this level, will modify all applicable settings.
A section at the bottom of the above screen displays the control keys for this screen.
Take note of these keys and their respective uses. Another section just below thecontrol keys section displays information on the currently highlighted item in the list.

Standard CMOS Setup
This “Standard CMOS Setup” option allows you to record some basic system hardware configuration and set the system clock and error handling. If the motherboard
is already installed in a working system, you will not need to select this option
anymore. However, if the configuration stored in the CMOS memory on the board
gets lost or damaged, or if you change your system hardware configuration, you willneed to respecify the configuration values. The configuration values usually get lostor corrupted when the power of the onboard CMOS battery weakens.

IV. BIOS(Standard CMOS)
The above screen provides you with a list of options. At the bottom of this screen
are the control keys for use on this screen. Take note of these keys and their respective uses.
User-configurable fields appear in a different color. If you need information on theselected field, press the <F1> key. The help menu will then appear to provide youwith the information you need. The memory display at the lower right-hand side of
the screen is read-only and automatically adjusts accordingly.

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Details of Standard CMOS Setup:
Date
To set the date, highlight the “Date” field and then press the page up/page down or+/- keys to set the current date. Follow the month, day and year format. Validvalues for month, day and year are:Month:Day:Year:

1 to 12
1 to 31
up to 2099

Time
To set the time, highlight the “Time” field and then press the page up/page down or+/- keys to set the current time. Follow the hour, minute and second format. Validvalues for hour, minute and second are:Hour:
Minute:Second:00 to 2300 to 59
00 to 59

time, just press the <Enter> key twice if you do not want to modify the current
You can bypass the date and time prompts by creating an AUTOEXEC.BAT file.
For information on how to create this file, please refer to the MS-DOS manual.

IV. BIOS(Standard CMOS)

Hard Disk Drives
This field records the specifications for all non-SCSI hard disk drives installed inyour system. The onboard PCI IDE connectors provide Primary and Secondary
channels for connecting up to four IDE hard disks or other IDE devices. Each channel can support up to two hard disks; the first of which is the “master” and thesecond is the “slave”.
Specifications for SCSI hard disks need not to be entered here since they operateusing device drivers and are not supported by any the BIOS. If you install theoptional PCI-SC200 SCSI controller card into the motherboard (see section VI for
instructions). If you install other vendor’s SCSI controller card, please refer to theirrespective documentations on how to install the required SCSI drivers.

ASUS P/I-P55T2P4 User’s Manual31IV. BIOS SOFTWAREFor IDE hard disk drive setup, you can:
• Use the Auto setting for detection during bootup.
• Use the IDE HDD AUTO DETECTION in the main menu to automaticallyenter the drive specifications.
• Enter the specifications yourself manually by using the “User” option.
The entries for specifying the hard disk type include CYLS (number of cylinders),
HEAD (number of read/write heads), PRECOMP (write precompensation), LANDZ(landing zone), SECTOR (number of sectors) and MODE. The SIZE field automatically adjusts according to the configuration you specify. The documentationthat comes with your hard disk should provide you with the information regarding
the drive specifications.
The MODE entry is for IDE hard disks only, and can be ignored for MFM and ESDI
drives. This entry provides three options: Normal, Large, LBA, or Auto (see below). Set MODE to the Normal for IDE hard disk drives smaller than 528MB; set
it to LBA for drives over 528MB that support Logical Block Addressing (LBA) toallow larger IDE hard disks; set it to Large for drives over 528MB that do not support LBA. Large type of drive can only be used with MS-DOS and is very uncommon. Most IDE drives over 528MB support the LBA mode.

IV. BIOS(Standard CMOS)

Auto detection of hard disks on bootup
For each field: Primary Master, Primary Slave, Secondary Master, and Secondary
Slave, you can select Auto under the TYPE and MODE fields. This will enable auto
detection of your IDE drives during bootup. This will allow you to change yourhard drives (with the power off) and then power on without having to reconfigure
your hard drive type. If you use older hard drives which do not support this feature,then you must configure the hard drive in the standard method as described aboveby the "User" option.

NOTE: After the IDE hard disk drive information has been entered into BIOS, new
IDE hard disk drives must be partitioned (such as with FDISK) and then formatted
before data can be read from and write on. Primary IDE hard disk drives must haveits partition set to active (also possible with FDISK).

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Drive A, Drive B
These fields record the types of floppy disk drives installed in your system. The
available options for drives A and B are:360KB, 5.25 in.
1.2MB, 5.25 in.
720KB, 3.5 in.
1.44MB, 3.5 in.
2.88MB, 3.5 in.
None

To enter the configuration value for a particular drive, highlight its corresponding
field and then select the drive type using the left- or right-arrow key.
Floppy 3 Mode Support
This is the Japanese standard floppy drive. The standard stores 1.2MB in a 3.5"
diskette. This is normally disabled but you may choose from either:
Drive A
Drive B
BothDisabled (Default)

IV. BIOS(Standard CMOS)Video
Set this field to the type of video display card installed in your system. The options
are:
EGA/VGA (Default)
Mono (for Hercules or MDA)CGA 40
CGA 80If you are using a VGA or any higher resolution card, choose the “EGA/VGA”
option.
Halt On
This field determines which types of errors will cause the system to halt.
All Errors (Default)
No Errors
All, But Keyboard
All, But Diskette
All, But Disk/Key

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IV. BIOS SOFTWARE
BIOS Features Setup
This “BIOS Features Setup” option consists of configuration entries that allow you
to improve your system performance, or let you set up some system features according to your preference. Some entries here are required by the motherboard’s design
to remain in their default settings.

IV. BIOS(BIOS Features)

A section at the lower right of the screen displays the control keys you can use. Take
note of these keys and their respective uses. If you need information on a particular
entry, highlight it and then press <F1>. A pop-up help menu will appear to provide
you with the information you need. To load the last set values, press <F5>. Pressing<F6> and <F7> load the BIOS default values and Setup default values, respectively.

Details of BIOS Features Setup:
Virus WarningThis field protects the boot sector and partition table of your hard disk against accidental modifications. Any attempt to write to them will cause the system to halt anddisplay a warning message. If this occurs, you can either allow the operation tocontinue or use a bootable virus-free floppy disk to reboot and investigate yoursystem. The default setting is Disabled. This setting is recommended because conflicts with new operating systems. Installation of new operating systems require thatyou disable this to prevent write errors.
CPU Internal Cache
These fields allow you to set the CPU’s “Level 1” primary cache to Enabled (default) or Disabled. Caching allows better performance.
External Cache
These fields allow you to set the CPU’s “Level 2” secondary cache to Enabled(default) or Disabled. Caching allows better performance.
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Quick Power On Self Test
This field speeds up the Power-On Self Test (POST) routine by skipping retesting asecond, third, and fourth time. Setup default setting for this field is Enabled. A
complete test of the system is done on each test.
HDD Sequence SCSI/IDE First
When using both SCSI and IDE hard disk drives, IDE is always the boot disk using
drive letter C (default setting of IDE). This feature allows a SCSI hard disk drive tobe the boot disk when set to SCSI. This allows multiple operating systems to be usedon both IDE and SCSI drives or the primary operating system to boot using a SCSI
hard disk drive.
Boot SequenceThis field determines where the system looks first for an operating system. Options
are C,CDROM,A; CDROM,C,A; A,C; C,A The setup default setting is to check first
the hard disk and then the floppy drive, that is, C, A.
Boot Up Floppy Seek
When enabled, the BIOS will seek the floppy “A” drive one time. By setup default,
this field is set to Disabled.

IV. BIOS(BIOS Features)

Floppy Disk Access Control
This allows protection of files from the computer system to be copied to floppy
drives by allowing the setting of Read Only to only allow reads from the floppy but
not writes. The setup default R/W allows both reads and writes.
IDE HDD Block Mode Sectors
This field enhances hard disk performance by making multi-sector transfers insteadof one sector per transfer. Most IDE drives, except older versions, can utilize thisfeature. By setup default, this field is set to HDD MAX, other selections are Disabled 2, 4, 8, 16, and 32.
Security Option
When you specify a Supervisor Password and/or User Password (explained later inthis section), the Security Option field determines when the system prompts for the
password. The default setting is System, where the system prompts for the User
Password every time you start your system. The other option is Setup, where thesystem goes through its startup routine unless the Setup utility is called, when thesystem prompts for the Supervisor Password.
PS/2 Mouse Function Control
The default of Auto allows the system to detect a PS/2 Mouse on bootup. If detected, IRQ12 will be used for the PS/2 Mouse. IRQ12 will be reserved for expansion cards if a PS/2 Mouse is not detected. Disabled will reserve IRQ12 for expansion cards and therefore the PS/2 Mouse will not function.

ASUS P/I-P55T2P4 User’s Manual35IV. BIOS SOFTWARE
PCI/VGA Palette Snoop
Some display cards that are nonstandard VGA such as graphics accelerators or MPEG
Video Cards may not show colors properly. The setting Enabled should correct thisproblem. Otherwise leave this on the setup default setting of Disabled.
OS/2 Onboard Memory > 64M
When using OS/2 operating systems with installed DRAM of greater than 64MB,
you need to Enable this option otherwise leave this on the setup default of Disabled.
......................................................................................................................................
Video ROM BIOS Shadow
This field allows you to change the video BIOS location from ROM to RAM. Relocating to RAM enhances system performance because information access is fasterthan to ROM. Setup default setting is Enabled.
C8000 – CBFFF Shadow to DC000 – DFFFF Shadow
These fields are used for shadowing other expansion card ROMs. If you installother expansion cards with ROMs on them, you will need to know which addresses
the ROMs use to shadow them specifically. Shadowing a ROM reduces the memory
available between 640KB and 1024KB by the amount used for this purpose. Leaveon default setting of Disabled.
......................................................................................................................................
Boot Up NumLock Status
This field enables users to activate the Number Lock function upon system boot.
The setup default setting for this field is On.
IV. BIOS(BIOS Features)

Boot Up System Speed
This has no function and should be left at the setup default of High.
Typematic Rate Setting
When enabled, you can set the two typematic controls listed below. Setup default
setting is Disabled.
Typematic Rate (Chars/Sec)This field controls the speed at which the system registers repeated keystrokes.
Options range from 6 to 30 characters per second. Setup default setting is 6; othersettings are 8, 10, 12, 15, 20, 24, and 30.
Typematic Delay (Msec)
This field sets the time interval, in milliseconds, for displaying the first and second
characters. Four delay rate options are available: 250 (default), 500, 750 and 1000.

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Chipset Features Setup(BIOS Features)This “Chipset Features Setup” option controls the configuration of the board’s chipset.
Control keys for this screen are the same as for the previous screen.

Auto Configuration
The default setting of 60ns DRAM sets the optimal timings for items 2 through 9 for
60ns DRAM modules. If you are using 70ns DRAM modules, you must change thisitem to 70ns DRAM. See pages 12-13 for DRAM installation information.
Peer Concurrency (Leave on default setting of Enabled)

IV. BIOS(Chipset Features)

PCI Streaming (Leave on default setting of Enabled)
Passive Release (Leave on default setting of Enabled)
Chipset Global Features (Leave on default setting of Enabled)
16-bit I/O Recovery Time
Timing for 16-bit ISA cards (Leave on default setting of 1 BUSCLK)
8-bit I/O Recovery Time
Timing for 8-bit ISA cards (Leave on default setting of 1 BUSCLK)Video BIOS Cacheable
Allows the Video BIOS to be cached to allow faster execution. (Leave on default
setting of Enabled)
Memory Hole At 15M-16M
Enabling this features reserves 15MB to 16MB memory address space to ISA expansion cards that specifically require this setting. This makes the memory from
15MB and up unavailable to the system. Expansion cards can only access memory
up to 16MB. The default is Disabled.

ASUS P/I-P55T2P4 User’s Manual37

IV. BIOS SOFTWARE[DRAM and ECC]
If all your DRAM modules have parity chips (e.g. 8 chips + 4 parity chips), they are
considered 36bits. This motherboard sums the memory per bank and therefore twomodules will give 72bits and the following will be displayed:

If your DRAM modules do not have parity chips (e.g. 8 chips), they are considered
32bits and the following will be displayed instead:(Chipset Features)

The default of Disabled for Memory parity SERR# (NMI) will not show memory
errors on your monitor. When using parity DRAM modules, you can select from thedefault of Parity or ECC (Error Checking and Correcting) to correct 1 bit memory
errors that may occur in the memory. (See pages 12-13 for more information on
DRAM memory modules.)......................................................................................................................................

IV. BIOS(Chipset Features)

Onboard FDC Controller
When enabled, this field allows you to connect your floppy disk drives to the onboard floppy drive connector instead of a separate controller card. If you want touse a different controller card to connect the floppy drives, set this field to “Disabled”. Default setting is Enabled.
Onboard FDC Swap A: B:
This field allows you to reverse the hardware drive letter assignments of your floppy
disk drives. Two options are available: No Swap (default) and Swap AB. If you want toswitch drive letter assignments through the onboard chipset, set this field to Swap AB.
Onboard Serial Port 1
Settings are 3F8H/IRQ4 (default), 2F8H/IRQ3, 3E8H/IRQ4, 2E8H/IRQ10, and Disabled for the onboard serial connector.
Onboard Serial Port 2
Settings are 3F8H/IRQ4, 2F8H/IRQ3 (default), 3E8H/IRQ4, 2E8H/IRQ10, and Disabled for the onboard serial connector.

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Onboard Parallel PortThis field sets the address of the onboard parallel port connector. You can selecteither: 3BCH / IRQ 7, 378H / IRQ 7 (default), 278H / IRQ 5, Disabled. If you installan I/O card with a parallel port, ensure that there is no conflict in the address assignments. The PC can support up to three parallel ports as long as there are no conflicts
for each port.
Parallel Port Mode
This field allows you to set the operation mode of the parallel port. The setting
Normal, allows normal-speed operation but in one direction only; EPP allows bidirectional parallel port operation at maximum speed; ECP allows the parallel port tooperate in bidirectional mode and at a speed faster than the maximum data transfer
rate; ECP+EPP (default) allows normal speed operation in a two-way mode.

IV. BIOS(Chipset Features)

ECP DMA SelectThis selection is available only if you select ECP or ECP+EPP in the
Parallel Port Mode. Select either DMA Channel 1, 3 (default), or Disabled.

IV. BIOS(Chipset Features)

UART2 Use Infrared
When enabled, this field activates the onboard infrared feature and sets the second
serial UART to support the infrared module connector on the motherboard. If yoursystem already has a second serial port connected to the onboard COM2 connector,
it will no longer work if you enable the infrared feature. By default, this field is set
to Disabled, which leaves the second serial port UART to support the COM2 serial
port connector. See section III for IrDA-Compliant Infrared Module Connector.
Onboard PCI IDE Enable
You can select to enable the Primary IDE channel, Secondary IDE channel, Both(default), or Disable both channels (for systems with only SCSI drives).
IDE 0 Master/Slave Mode, IDE 1 Master/Slave Mode
Each channel (0 and 1) has both a master and a slave making four IDE devices
possible. Because each IDE device may have a different Mode timing (0, 1, 2, 3, 4),
it is necessary for these to be independent. The default setting of Auto will allow
autodetection to ensure optimal performance.

ASUS P/I-P55T2P4 User’s Manual39IV. BIOS SOFTWARE
Power Management Setup
This “Power Management Setup” option allows you to reduce power consumption.
This feature turns off the video display and shuts down the hard disk after a period
of inactivity.

IV. BIOS(Chipset Features)

Details of Power Management Setup:

IV. BIOS(Power Management)

Power Management (User Define)This field acts as the master control for the power management modes. User Define
allows you to set power saving options according to your preference; Disable disables the power saving features; Min Saving puts the system into power saving mode
after a long period of system inactivity; Max Saving puts the system into powersaving mode after a brief period of system inactivity.
IMPORTANT: Advanced Power Management (APM) should be installed tokeep the system time updated when the computer enters suspend mode activated by the BIOS Power Management. For DOS environments, you need to
add DEVICE=C:\DOS\POWER.EXE in you CONFIG.SYS. For Windows 3.1x
and Windows 95, you need to install Windows including the APM feature. A
battery and power cord icon labeled "Power" will appear in the “Control Panel.”Choose “Advanced” in the Power Management Field.
Video Off Option (Susp,Stby -> Off )This field determines when to activate the video off feature for monitor power management. The settings are Susp,Stby -> Off, All Modes -> Off, Always On, and Suspend -> Off.
Video Off Method (DPMS OFF)This field defines the video off features. The following options are available: DPMS
OFF, DPMS Reduce ON, Blank Screen, V/H SYNC+Blank, DPMS Standby, andDPMS Suspend. The DPMS (Display Power Management System) features allow
the BIOS to control the video display card if it supports the DPMS feature. Blank
Screen only blanks the screen (use this for monitors without power management or“green” features. If set up in your system, your screen saver will not display with
Blank Screen selected). V/H SYNC+Blank blanks the screen and turns off verticaland horizontal scanning.

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Suspend Switch
This field enables or disables the SMI connector on the motherboard. This connector connects to the lead from the Suspend switch mounted on the system case. Default setting for this field is Enable.
Doze Speed (div by), Stdby Speed (div by)
These two fields set the CPU speed during each mode. The number indicates what
the normal CPU speed is divided by.
PM Timers
This section controls the time-out settings for the Power Management scheme. The
fields included in this section are “HDD Power Down”, which places the hard disk
into its lowest power consumption mode, and the Doze Mode, Standby Mode andSuspend Mode.
The system automatically “wakes up” from any power saving mode when there issystem activity such as when a key is pressed from the keyboard, or when there is
activity detected from the enabled IRQ channels.
HDD Power Down shuts down any IDE hard disk drives in the system after a period of inactivity. This time period is user-configurable to Disable or from 1 Min to
15 Min. This feature does not affect SCSI hard drives.
IV. BIOS(Power Management)

The Doze Mode, Standby Mode, and Suspend Mode fields set the period of timeafter which each of these modes activate: 30 sec, 1 Min, 2 Min, 4 Min, 8 Min, 20
Min, 30 Min, 40 Min, 1 Hour.
PM Events
This section sets the wake-up call of the system. If activity is detected from any
enabled IRQ channels in the left-hand group, the system wakes up from suspended
mode. You can enable power management for IRQ 3-IRQ15 individually in the listat the right of the screen. The power management feature will work on the enabled
IRQ channels.
NOTE: A Microsoft serial mouse or compatible will use either COM1 (IRQ4)
or COM2 (IRQ3), and a PS/2 mouse will use IRQ12. If you know which IRQ
your mouse is using, you can enable the wake-up Event for that IRQ here andthe system will wake up when you move the mouse or click its button.
.......................................................................................................................................
IRQ3 (device)-IRQ15 (device)
You can individually Enable or Disable each IRQ to include in the sleep function.
IRQ8 (RTC Alarm) is usually set to Disable so that any software alarm clock or
event calendar can wake up the system.

ASUS P/I-P55T2P4 User’s Manual41IV. BIOS SOFTWAREPNP and PCI Setup
This “PNP and PCI Setup” option configures the PCI bus slots. All PCI bus slots on
the system use INTA#, thus all installed PCI cards must be set to this value.

PNP OS Installed
This field allows you to use a Plug-and-Play (PnP) operating system to configure
the PCI bus slots instead of using the BIOS. Default setting is No.

IV. BIOS(Plug & Play / PCI)

Slot 1 (RIGHT) IRQ to Slot 4 (LEFT) IRQ
These fields set how IRQ use is determined for each PCI slot. The default setting foreach field is Auto, which uses auto-routing to determine IRQ use. The other options aremanual settings of NA, 5, 7, 9, 10, 11, 12, 14 or 15 for each slot.
PCI Latency Timer
The default setting of “32 PCI Clock” enables maximum PCI performance for thismotherboard.
IRQ xx Used By ISA
These fields indicate whether or not the displayed IRQ for each field is being usedby a legacy (non-PnP) ISA card. Two options are available: No/ICU and Yes. The
first option, the default value, indicates either that the displayed IRQ is not used oran ISA Configuration Utility (ICU) is being used to determine if an ISA card isusing that IRQ. If you install a legacy ISA card that requires a unique IRQ, and you
are not using an ICU, you must set the field for that IRQ to Yes. For example: If you
install a legacy ISA card that requires IRQ 10, then set IRQ10 Used By ISA to Yes.
......................................................................................................................................

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ASUS P/I-P55T2P4 User’s ManualIV. BIOS SOFTWAREDMA x Used By ISA
These fields indicate whether or not the displayed DMA channel for each field isbeing used by a legacy (non-PnP) ISA card. Available options include: No/ICU andYes. The first option, the default setting, indicates either that the displayed DMA
channel is not used or an ICU is being used to determine if an ISA card is using thatchannel. If you install a legacy ISA card that requires a unique DMA channel, andyou are not using an ICU, you must set the field for that channel to Yes.

(Power Management)

ISA MEM Block BASE
This field allows you to set the base address and block size of a legacy ISA card thatuses any memory segment within the C800H and DFFFH address range. If you
have such a card, and you are not using an ICU to specify its address range, select abase address from the six available options; the ISA MEM Block SIZE field willthen appear for selecting the block size. If you have more than one legacy ISA cardin your system that requires to use this address range, you can increase the block
size to either 8K, 16K, 36K, or 64K. If you are using an ICU to accomplish this task,
leave ISA MEM Block BASE to its default setting of No/ICU.
SYMBIOS SCSI BIOS
The default uses Auto settings for the onboard SCSI BIOS. If you do not want to use
the onboard SCSI BIOS, choose Disabled

ASUS P/I-P55T2P4 User’s Manual

IV. BIOS(Plug & Play / PCI)

USB Function
This motherboard supports Universal Serial Bus (USB) devices but current operating systems do not. The default is set to Disabled until support disks and USB
devices are available in which time you can set this function to Enabled.

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IV. BIOS SOFTWARE
Load BIOS Defaults
This “Load BIOS Defaults” option allows you to load the troubleshooting default
values permanently stored in the BIOS ROM. These default settings are non-optimal and disable all high performance features. To load these default settings, highlight “Load BIOS Defaults” on the main screen and then press the <Enter> key. The
system displays a confirmation message on the screen. Press the <Y> key and thenthe <Enter> key to confirm. Press the <N> key and then the <Enter> key to abort.
This feature does not affect the fields on the Standard CMOS Setup screen.

Load Setup Defaults
This “Load Setup Defaults” option allows you to load the default values to the system configuration fields. These default values are the optimized configuration settings for the system. To load these default values, highlight “Load Setup Defaults”
on the main screen and then press <Enter>. The system displays a confirmation
message on the screen. Press <Y> and then <Enter> to confirm. Press <N> andthen <Enter> to abort. This feature does not affect the fields on the Standard CMOS
Setup screen.

IV. BIOS(Load Defaults)
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Supervisor Password and User Password

IV. BIOS(Passwords)

These two options set the system passwords. “Supervisor Password” sets a password that will be used to protect the system and the Setup utility; “User Password”
sets a password that will be used exclusively on the system. By default, the systemcomes without any passwords. To specify a password, highlight the type you want
and then press <Enter>. A password prompt appears on the screen. Taking note thatthe password is case sensitive, and can be up to 8 alphanumeric characters long, typein your password and then press <Enter>. The system confirms your password byasking you to type it again. After setting a password, the screen automatically reverts to the main screen.

To implement the password protection, specify in the “Security Option” field of theBIOS Features Setup screen when the system will prompt for the password. If you
want to disable either password, press <Enter> instead of entering a new password
when the “Enter Password” prompt appears. A message confirms the password has
been disabled.

NOTE: If you forget the password, see CMOS RAM in section III for procedureson clearing the CMOS.

ASUS P/I-P55T2P4 User’s Manual45IV. BIOS SOFTWAREIDE HDD Auto Detection
This “IDE HDD Auto Detection” option detects the parameters of an IDE hard disk
drive, and automatically enters them into the Standard CMOS Setup screen.

IV. BIOS(Hard Drive Detect)

Up to four IDE drives can be detected, with parameters for each listed inside thebox. To accept the optimal entries, press <Y>, otherwise select from the numbers
displayed under the OPTIONS field (2, 1, 3 in this case); to skip to the next drive,press <N>. If you accept the values, the parameters will appear listed beside thedrive letter on the screen. The process then proceeds to the next drive letter. Pressing <N> to skip rather than to accept a set of parameters causes the program to enterzeros after that drive letter.
Remember that if you are using another IDE controller that does not feature Enhanced IDE support for four devices, you can only install two IDE hard disk drives.
Your IDE controller must support the Enhanced IDE features in order to use Drive E
and Drive F. The onboard PCI IDE controller supports Enhanced IDE, with twoconnectors for connecting up to four IDE devices. If you want to use another controller that supports four drives, you must disable the onboard IDE controller in the
Chipset Features Setup screen.
When autodetection is completed, the program automatically enters all entries you
accepted on the field for that drive in the Standard CMOS Setup screen. Skipped
entries are ignored and are not entered in the screen.
If you are autodetecting a hard disk that supports the LBA mode, three lines willappear in the parameter box. Choose the line that lists LBA for an LBA drive. Do
not select Large or Normal.
The autodetection feature can only detect one set of parameters for a particular IDE
hard drive. Some IDE drives can use more than one set. This is not a problem if thedrive is new and there is nothing on it.

46

ASUS P/I-P55T2P4 User’s ManualIV. BIOS SOFTWAREIMPORTANT: If your hard disk was already formatted on an older previous
system, incorrect parameters may be detected. You will need to enter the correct parameters manually or use low-level format if you do not need the datastored on the hard drive.
If the parameters listed differ from the ones used when the drive was formatted, thedrive will not be readable. If the auto-detected parameters do not match the ones
that should be used for your drive, do not accept them. Press <N> to reject thepresented settings and enter the correct ones manually from the Standard CMOS
Setup screen.

Save & Exit Setup

IV. BIOS(Save & Exit)

IV. BIOS(Load Setup Defaults)

Select this option to save into the CMOS memory all modifications you specified
during the current session. To save the configuration changes, highlight the “Save& Exit Setup” option on the main screen and then press <Enter>.

Exit Without Saving
Select this option to exit the Setup utility without saving the modifications you specify
during the current session. To exit without saving, highlight the “Exit Without Saving” option on the main screen and then press <Enter>.

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V. DESKTOP MANAGEMENTDesktop Management Interface (DMI)
Introducing the ASUS DMI Configuration Utility

System Requirements
The motherboard BIOS must support DMI. The following motherboards do notsupport DMI:
• P/I-P6RP4• PCI/E-P54NP4• PCI/I-P54NP4D(not supported)(not supported)(not supported)
V. DMI(DMI Introduction)(Flash Memory Writer)

This motherboard supports DMI within the BIOS level and provides a DMI Configuration Utility to maintain the Management Information Format Database (MIFD).
DMI is able to auto-detect and record information pertinent to a computer’s systemsuch as the CPU type, CPU speed, and internal/external frequencies, and memory
size. The onboard BIOS will detect as many system information as possible andstore those collected information in a 4KB block in the motherboard’s Flash EPROM
and allow the DMI to retrieve data from this database. Unlike other BIOS software,
the BIOS on this motherboard uses the same technology implemented for Plug andPlay to allow dynamic real-time updating of DMI information versus creating a new
BIOS image file and requiring the user to update the whole BIOS. This DMI Configuration Utility also allows the system integrator or end user to add additional
information into the MIFD such as serial numbers, housing configurations, and vendor information. Those information not detected by the motherboard BIOS and has
to be manually entered through the DMI Configuration Utility and updated into the
MIFD. This DMI Configuration Utility provides the same reliability as PnP updating and will prevent the refreshing failures associated with updating the entire BIOS.

The DMI Configuration Utility (DMICFG.EXE) must be ran in real mode in orderfor the program to run, the base memory must be at least 180K. Memory managers
like HIMEM.SYS (required by windows) must not be installed. You can boot up
from a system diskette without AUTOEXEC.BAT and CONFIG.SYS files, “REM”
HIMEM.SYS in the CONFIG.SYS, or press <F5> during bootup to bypass your
AUTOEXEC.BAT and CONFIG.SYS files.

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V. DESKTOP MANAGEMENT
Using the ASUS DMI Configuration Utility
Edit DMI (or delete)

Use the ←→ (left-right) cursors to move the top menu items and the ↑↓ (up-down)
cursor to move between the left hand menu items. The bottom of the screen willshow the available keys for each screen. Press enter at the menu item to enter theright hand screen for editing. “Edit component” appears on top. The reversed color
field is the current cursor position and the blue text are available for editing. Theorange text shows auto-detected information and are not available for editing. The
blue text “Press [ENTER] for detail” contains a second pop-up menu is available,
use the + - (plus-minus) keys to change the settings. Enter to exit and save, ESC toexit and not save.

V. DMI(Using DMI Utility)

If the user has made changes, ESC will prompt you to answer Y or N. Enter Y to go
back to the left-hand screen and save, enter N to go back to left-hand screen and not
save. If editing has not been made, ESC will send you back to the left hand menu
without any messages.

Notes:
A heading, *** BIOS Auto Detect *** appears on the right for each menu item on
the left side that has been auto detected by the system BIOS.
A heading, *** User Modified *** will appear on the right for menu items that has
been modified by the user.

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V. DESKTOP MANAGEMENT
Save MIFD

You can save the MIFD (normally only saved to flash ROM) to a file by entering thedrive and path here. If you want to cancel save, you may press ESC and a message“Bad File Name” appears here to show it was not saved.
Load MIFD

You can load the disk file to memory by entering a drive and path and file namehere.

V. DMI(Using DMI Utility)

Load BIOS Defaults

You can load the BIOS defaults from a MIFD file and can clear all user modified
and added data. You must reboot your computer in order for the defaults to be saved
back into the Flash BIOS.

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VI. ASUS PCI SCSI Cards
VI. ASUS SCSI Cards(SCSI BIOS)

Symbios SCSI BIOS and Drivers
Aside from the system BIOS, the Flash memory chip on the motherboard also contains the Symbios SCSI BIOS. This Symbios SCSI BIOS works in conjunction withthe optional ASUS PCI-SC200 controller card to provide Fast SCSI-2 interface whenusing compatible SCSI devices or the ASUS PCI-SC860 SCSI controller cards toprovide Ultra-Fast SCSI-2 interface when using Ultra-Fast SCSI-2 devices.
All SCSI devices you install on your system require driver software to function.
The Symbios SCSI BIOS directly supports SCSI hard disks under the DOS, Windows and OS/2 environments. It also uses device drivers from the DOS floppy disk
included in the ASUS PCI-SC200 and ASUS PCI-SC860 controller card packages
to support hard disks and other SCSI devices working under DOS, Microsoft Windows, Microsoft Windows NT, Novell NetWare and IBM OS/2. These drivers provide higher performance than the direct BIOS support. To use these drivers, youmust install them into your system and add them to your system configuration files.
Driver support for SCSI devices used with SCO UNIX is also provided. These
drivers are included in the second SCO UNIX floppy disk. Windows 95 support isalso available using the device drivers included within the Windows software. The
ASUS PCI-SC200 and ASUS PCI-SC860 are Plug and Play adapters that are auto
detected by BIOS and current operating systems that support Plug and Play features.
For information about these drivers and their usage, please view the Readme files
included in the driver packages.

ASUS PCI-SC200 & PCI-SC860 SCSI Cards
The ASUS PCI-SC200 or the ASUS PCI-SC860 may be bundled with your motherboard or purchased separately. Both cards provide the option of connecting internalor external SCSI devices for a total of 7 devices on each SCSI card.

ASUS P/I-P55T2P4 User's Manual53VI. ASUS PCI SCSI Cards
VI. ASUS SCSI Cards(Setup)Setting Up the ASUS PCI-SC200 & PCI-SC860
There are two jumper settings you may need to make on the ASUS PCI-SC200 to set
it up. One setting assigns the PCI INT interrupt, the other sets the card’s termination.
The ASUS PCI-SC860 has no jumper settings but you should read the “Terminator
Requirements.”

Setting the INT Assignment for the ASUS PCI-SC200
You must use PCI INT A setting in order to properly assign the ASUS PCI-SC200's
interrupt. On the ASUS PCI-SC200, you assign the INT by setting jumper JP1 or
JP2. The default setting for the card already is INT A, so you do not need to change
the setting to use the ASUS PCI-SC200 with this motherboard.

JPJP
1 2

JPJP
1 2
1
2
3

JPJP
1 2
1
2
3

INT A (Def) INT B

JPJP
1 2
1
2
3

INT C

1
2
3
INT D

Interrupt Settings (A, B, C, or D)

Terminator Requirements for SCSI Devices
SCSI devices are connected together in a “chain” by cables. Internal devices connect to the ASUS PCI-SC200 or ASUS PCI-SC860 with a fifty-pin flat ribbon cable.
External devices connect to the external port with a SCSI-2 cable. If there are morethan one internal or external devices, additional devices are connected with cables
to form a “daisy chain.” Terminating the devices on the ends of the SCSI Bus “chain”
is necessary for SCSI devices to work properly. Termination of the devices between
the ends must be Disabled.

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VI. ASUS PCI SCSI Cards
VI. ASUS SCSI Cards(Jumpers)

Terminator Settings for the ASUS PCI-SC860
Many SCSI devices including the ASUS PCI-SC860 use a set of onboard terminating resistors to terminate the devices at the ends automatically. Automatic termination requires that the SCSI devices be connected in a straight linear connection or“chain.” Connect SCSI devices to one or two of the SCSI connectors in a linear“chain” for auto termination of the ASUS PCI-SC860 to be effective. Other formations will cause your SCSI devices to not mount properly. You must use the end of
the ribbon cable when using the internal connector(s) to keep a linear path.
Additional Note: The Symbios Logic SCSI Configuration Utility is a powerfultool. If, while using it, you somehow disable all your controllers or cannot enter
the configuration utility, pressing “Ctrl-A” after memory count during reboot
allows you to recover and reconfigure.

Terminator Settings for the ASUS PCI-SC200
The ASUS PCI-SC200, on the other hand, has “active” termination that you must
set using jumper JP5. There are two settings, "terminated" and "not terminated," asshown below.
Decide whether or not you need to terminate the ASUS PCI-SC200 based on its
position in the SCSI chain. Only the devices at each end of the chain need to beterminated. If you have only internal or only external devices connected to the
ASUS PCI-SC200, then you must terminate the ASUS PCI-SC200. If you haveboth internal and external devices connected, you must not terminate the card. See
the following example which illustrates this concept.

JP
5

JP
5

Terminated (Default)

Not TerminatedTerminator Setting (Terminated / Not Terminated)

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VI. ASUS PCI SCSI Cards
VI. ASUS SCSI Cards(SCSI ID Numbers)

SCSI Device 1

SCSI Device 2
Termination Required(End Device)

Termination Required(JP5 Open)SCSI Device 3

SCSI Device 4
Termination Required(End Device)

No Termination Required(JP5 Short)

Termination Required(End Device)
SCSI Device 2

SCSI Device 1

SCSI ID Numbers for SCSI Devices
All SCSI devices, including the ASUS PCI-SC200 and ASUS PCI-SC860 interface
card must have a SCSI identification number that is not in use by any other SCSI
device. There are eight possible ID numbers, 0 through 7. The ASUS PCI-SC200 and
ASUS PCI-SC860 cards have fixed SCSI IDs of 7. The SCSI ID serves two purposes:••

It uniquely defines each SCSI device on the bus.
It determines which device controls the bus when two or more devices try to use
it at the same time.

SCSI IDs on one channel do not interfere with the IDs on another channel. This applies to two SCSI host adapters that implement different buses as well as dual channels
on a single host adapter. You can connect up to seven SCSI devices to the interfacecard. You must set a SCSI ID number (ID 0 to ID 6) for each device. SCSI devices
vary in how they set the ID number. Some use jumpers, others have some kind of
selector switch. Refer to the manual for any device you install for details on how to set
its ID number.

SCSI ID Priority
The ASUS PCI-SC200 and ASUS PCI-SC860 are 8bit single-channel SCSI cards.
SCSI ID 7 has the highest priority, and SCSI ID 0 has the lowest priority.

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ASUS P/I-P55T2P4 User's Manual

VII. ASUS I-A16C Audio Card
NOTE: The ASUS I-A16C 16-bit ISA audio card comes with certain motherboard
packages and is not for sale separately.

ASUS I-A16C Audio Features
Creative Labs ViBRA 16C PnP Audio Chip
Full Duplex Supports
16/8 bit PCM 5KHz to 44.1KHz
Wave Table Upgradeable
Software Includes:
DOS and Window 3.1 Drivers
Windows 95 Driver
Wave Editor
Wave OLE
Quick CD
Mixer Control
Quick PlayerVII. ASUS I-A16C(Features / Precautions)

•
•
•
•
•

Unpacking and Handling Precautions
CAUTION: Keep the ASUS I-A16C stored in its anti-static bag until you are readyto install it in your system. The ASUS I-A16C is easily damaged by static electricity. Observe the following precautions while unpacking and handling the board:•••

Before handling the board, discharge static electricity form your body by touching an unpainted area of the system's metal chassis. While installing the board,ground yourself frequently to discharge any static electricity that may accumulate in your body.
After removing the board form the anti-static bag, place it on a grounded surface with the components facing up.
Check the board for damage. If any socketed component appears loose, press
firmly but carefully to seat the chip in its socket. Otherwise, avoid touching
the components on the board. Always handle the board by the edges.

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VII. ASUS I-A16C Audio Card
Layout and Connectors
Mitsumi Audio In
Sony Audio In

Panasonic Audio In
PC Speaker In
Volume Control

Wave Table Upgrade
PC Speaker Out

Speaker Out
Line OutVII. ASUS I-A16C(Layout / Connectors)

Line In
Microphone

MIDI/Game

Connectors
The audio input connectors are used when you wish to control software mixer settings (bass, treble, volume, etc.) for audio CD's that are played with your CD-ROM.
If the "Audio Out" from the CD-ROM is not connected to the "Audio In" on thecard, you can only use the direct output located in the front panel of the CD-ROM
and adjust volume level by the knob.

CD-Audio Connector Pin Definitions

58

Sony Audio In
Pin Definitionl Right Signal
2 Ground
3 Ground4 Left Signal

Mitsumi Audio In
Pin Definition
1 Ground2 Left Signal
3 Ground4 Right Signal

Panasonic Audio In
Pin Definition
1 Left Signal
2 Ground3 Right Signal-- ----PC Speaker In
Pin Definition
1 Mono Signal
2 Ground-- ----- ----- ----PC Speaker Out
Pin Definition
1 Right Signal
2 Ground3 Left Signal
4 Ground-- ----

Volume Control
Pin Definition
1 Ground2 Volume Up
3 Ground
4 Volume Down
5 Ground

ASUS P/I-P55T2P4 User's Manual