AOpen P5TC-HW User Manual

Chapter 2

Hardware Installation

This chapter gives you a step-by-step procedure on how to install your system.
Follow each section accordingly.

Caution: Electrostatic discharge (ESD) can
damage your processor, disk drives, expansion
boards, and other components. Always
observe the following precautions before you
install a system component.

1. Do not remove a component from its
protective packaging until you are ready
to install it.

2. Wear a wrist ground strap and attach it to
a metal part of the system unit before
handling a component. If a wrist strap is
not available, maintain contact with the
system unit throughout any procedure
requiring ESD protection.

2-1

Hardware Installation

2.1 Jumpers and Connector Locations

The following figure shows the locations of the jumpers and connectors on the
system board:

I
S
A

3

HDD LED

PANEL

USB

KB1

PS2 MS

P
C
I
4

SB-LINK

BIOS

P
C
I

3

IrDA

PWR1

P

P

C

C

I

I

1

2

IDE1

I

I

S

S

A

A

2

1

FDC

IDE2

COM2

COM1

S

I
M
M

1

PRINTER

D

D

I

I

S

S

S

I

I

M

M

M

M

M

M

3

2

M

M

I

M

M

2

1

4

PiiX4

SW1

JP14

TX

JP4

FAN

JP12

JP5
JP6

2-2

Hardware Installation

Jumpers

SW1: DIP Switch for CPU voltage and clock ratio
JP4,JP5,JP6: CPU external (bus) clock
JP12: I/O Voltage
JP14: Clear CMOS

Connectors

KB1: AT keyboard connector
PWR1: AT (PS/2) power connector
PS2 MS: PS/2 mouse connector
USB: USB connector
COM1: COM1 connector
COM2: COM2 connector
FDC: Floppy drive connector
PRINTER: Printer connector
IDE1: IDE1 primary channel
IDE2: IDE2 secondary channel
FAN: CPU fan connector
IrDA: IrDA (Infrared) connector
HDD LED: HDD LED connector
PANEL: Front panel (Multifunction) connector
SB-LINK: Creative PCI sound card connector

2-3

Hardware Installation

3

3

2.2 Jumpers

Jumpers are made by pin headers and plastic connecting caps for the purpose of
customizing your hardware. Doing so requires basic knowledge of computer
hardware, be sure you understand the meaning of the jumpers before you change
any setting. The onboard jumpers are normally set to their default with optimized
settings.

On the mainboard, normally there is a bold line marked beside pin 1 of the jumper,
sometimes, there are numbers also. If we connect (short) plastic cap to pin 1 and
2, we will say set it at 1-2, and when we say jumper is open, that means no plastic
cap connected to jumper pins.

Open

1
2

Short

1
2

Jumper set at 1-2

1
2

Jumper set at 2-3

1
2

2-4

2.2.1 Setting the CPU Voltage

ON

ON

ON

ON

ON

ON

S4

ON
OFF
OFF
ON
OFF
OFF
OFF

S5

ON
ON
OFF
OFF
OFF
ON
ON

S6

ON
ON
ON
OFF
OFF
OFF
OFF

S7

ON
ON
ON
ON
ON
OFF

ON

S8

OFF
OFF
OFF
OFF
OFF
OFF
ON

Vcore

3.52V

3.45V

3.2V

2.9V

2.8V

2.2V

1.8V

Hardware Installation

SW1 is used to select CPU core
voltage (Vcore) and ratio, there
are totally eight switches on the
DIP. After installing a CPU,
remember to set the switch 4-8
to specify a proper Vcore.

1 2 3 4 5 6 7 8

2.9V

K6-166/200 or M2

1 2 3 4 5 6 7 8

2.8V

Intel P55C (MMX)

1 2 3 4 5 6 7 8

3.52V

Cyrix 6x86 or AMD K5

1 2 3 4 5 6 7 8

3.45V

Intel P54C or IDT C6

1 2 3 4 5 6 7 8

3.2V

AMD K6-233

ON

1 2 3 4 5 6 7 8

2.2V

K6-266/300

1 2 3 4 5 6 7 8

1.8V

Reserved for future use

2-5

Hardware Installation

Warning: Please make sure that you have installed CPU fan
properly if Intel PP/MT-233 or AMD K6 CPU is being selected
to use. It may cause your system unstable if you can not meet
the heat dissipation requirement from above CPU type. It is
recommended to adopt larger fan on these CPU for better air
flow in the system. Please refer to AOpen 's web site
(http://www.aopen.com.tw) to choose a proper CPU fan.

Tip: Normally, for single voltage CPU, Vcpuio (CPU I/O
Voltage) is equal to Vcore, but for CPU that needs dual voltage
such as PP/MT (P55C) or Cyrix 6x86L, Vcpuio is different from
Vcore and must be set to Vio (PBSRAM and Chipset Voltage).
The single or dual voltage CPU is automatically detected by
hardware circuit.

Tip: For supporting more different CPUs in future, this
motherboard uses five switchs to specify Vcore. There are 32
settings totally, and the range is from 1.3V to 3.5V.

CPU Type S4 S5 S6 S7 S8 Vcore

INTEL P54C Single Voltage OFF ON ON ON OFF 3.45V
INTEL MMX P55C Dual Voltage OFF OFF OFF ON OFF 2.8V
AMD K5 Single Voltage ON ON ON ON OFF 3.52V
AMD K6-166/200 Dual Voltage ON OFF OFF ON OFF 2.9V
AMD K6-233 Dual Voltage OFF OFF ON ON OFF 3.2V
AMD K6-266/300 Dual Voltage OFF ON OFF OFF OFF 2.2V
Cyrix 6x86 Single Voltage ON ON ON ON OFF 3.52V
Cyrix 6x86L Dual Voltage OFF OFF OFF ON OFF 2.8V
Cyrix M2 Dual Voltage ON OFF OFF ON OFF 2.9V
IDT C6 Single Voltage OFF ON ON ON OFF 3.45V

2-6

Hardware Installation

This motherboard supports the CPU core voltage from 1.3V to 3.5V, that can be
applied to the various CPU type in future. For your reference, all settings are
listed in the following table.

Vcore

1.30V

1.35V

1.40V

1.45V

1.50V

1.55V

1.60V

1.65V

1.70V

1.75V

1.80V

1.85V

1.90V

1.95V

2.00V

2.05V

2.0V

2.1V

2.2V

2.3V

2.4V

2.5V

2.6V

2.7V

2.8V

2.9V

3.0V

3.1V

3.2V

3.3V

3.4V

3.5V

S4

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

OFF

ON

S5

OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON
OFF
OFF

ON

ON

S6

OFF
OFF
OFF
OFF

ON
ON
ON

ON
OFF
OFF
OFF
OFF

ON

ON

ON

ON
OFF
OFF
OFF
OFF

ON

ON

ON

ON
OFF
OFF
OFF
OFF

ON

ON

ON

ON

S7

OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF

ON
ON
ON
ON
ON
ON
ON

ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF

ON

ON

ON

ON

ON

ON

ON

ON

S8

ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON

ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF

2-7

Hardware Installation

JP12

1-2
3-4

I/O Voltage (Vio)

3.3 (default)

3.45V

JP12 is reserved for testing purposes only.
This jumper enables you to set the voltage of
the onboard chipset and PBSRAM (Vio). For
dual-voltage CPU, JP12 also functions as
CPU I/O voltage (Vcpuio) controller.

JP12

1 2 3

3.3V

(default)

JP12

1 2 3

3.45V

2.2.2 Selecting the CPU Frequency

Intel Pentium, Cyrix 6x86, AMD K5/K6 and IDT C6 CPU are designed to have
different Internal (Core) and External (Bus) frequency.

Core frequency = Ratio * External bus clock

2-8

S1

OFF
ON
ON
OFF
ON
ON
OFF

S2

OFF
OFF
ON
ON
OFF
ON
ON

S3

OFF
OFF
OFF
OFF
ON
ON
ON

CPU Frequency
Ratio

1.5x (3.5x)
2x

2.5x (1.75x)
3x
4x

4.5x

5x

Note: Intel PP/MT MMX 233MHz is using 1.5x jumper setting
for 3.5x frequency ratio, and AMD PR166 is using 2.5x
setting for 1.75x frequency ratio.

The ratio of Core/Bus frequency
is selected by the switch 1-3 of
SW1.

Hardware Installation

ON

ON

ON

ON

ON

ON

ON

JP4

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

JP5

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

1 2 3 4 5 6 7 8

1.5x (3.5x)

1 2 3 4 5 6 7 8

2x

1 2 3 4 5 6 7 8

2.5x (1.75x)

1 2 3 4 5 6 7 8

1 2 3 4 5 6 7 8

4x

1 2 3 4 5 6 7 8

4.5x

1 2 3 4 5 6 7 8

5x

3x

Note: Intel PP/MT 233MHz is using 1.5x jumper setting for

3.5x frequency ratio, and AMD PR166 is using 2.5x setting for

1.75x frequency ratio.

JP6

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

CPU External Clock

60MHz
66MHz
75MHz

83.3MHz

JP4, JP5 and JP6 are the
selections of CPU external
clock (bus clock), which is
actually the clock from clock
generator.

JP4 JP5 JP6

1 2 3 1 2 3 1 2 3

60MHz

JP4 JP5 JP6

1 2 3 1 2 3 1 2 3

75MHz

JP4 JP5 JP6

1 2 3 1 2 3 1 2 3

66MHz

JP4 JP5 JP6

1 2 3 1 2 3 1 2 3

83.3mhz

2-9

Hardware Installation

Warning: INTEL TX chipset supports only 60/66MHz
external CPU bus clock, the 75/83.3MHz settings are for
internal test only, set to 75/83.3MHz exceeds the

specification of TX chipset, which may cause serious
system damage.

Caution: Following table are possible settings of current

CPU available on the market. The correct setting may
vary because of new CPU product, refer to your CPU
specification for more details.

Warning: Cyrix 6x86 P200+ uses 75MHz external clock,
the jumper setting shown on the table below is for user's
convenient. It may cause serious system damage to use
75MHz clock.

INTEL
Pentium

P54C 90 90MHz = 1.5x 60MHz OFF OFF OFF 1-2 & 2-3 & 1-2
P54C 100 100MHz = 1.5x 66MHz OFF OFF OFF 2-3 & 1-2 & 1-2
P54C 120 120MHz = 2x 60MHz ON OFF OFF 1-2 & 2-3 & 1-2
P54C 133 133MHz = 2x 66MHz ON OFF OFF 2-3 & 1-2 & 1-2
P54C 150 150MHz = 2.5x 60MHz ON ON OFF 1-2 & 2-3 & 1-2
P54C 166 166MHz = 2.5x 66MHz ON ON OFF 2-3 & 1-2 & 1-2
P54C 200 200MHz = 3x 66MHz OFF ON OFF 2-3 & 1-2 & 1-2

INTEL
Pentium
MMX

PP/MT 150 150MHz = 2.5x 60MHz ON ON OFF 1-2 & 2-3 & 1-2
PP/MT 166 166MHz = 2.5x 66MHz ON ON OFF 2-3 & 1-2 & 1-2
PP/MT 200 200MHz = 3x 66MHz OFF ON OFF 2-3 & 1-2 & 1-2
PP/MT 233 233MHz = 3.5x 66MHz OFF OFF OFF 2-3 & 1-2 & 1-2

AMD K5 CPU Core

PR90 90MHz = 1.5x 60MHz OFF OFF OFF 1-2 & 2-3 & 1-2
PR100 100MHz = 1.5x 66MHz OFF OFF OFF 2-3 & 1-2 & 1-2
PR120 90MHz = 1.5x 60MHz OFF OFF OFF 1-2 & 2-3 & 1-2
PR133 100MHz = 1.5x 66MHz OFF OFF OFF 2-3 & 1-2 & 1-2
PR166 116MHz = 1.75x 66MHz ON ON OFF 2-3 & 1-2 & 1-2

CPU Core
Frequency

CPU Core
Frequency

Frequency

Ratio External

Bus Clock

Ratio External

Bus Clock

Ratio External

Bus Clock

S1 S2 S3 JP4 & JP5 & JP6

S1 S2 S3 JP4 & JP5 & JP6

S1 S2 S3 JP4 & JP5 & JP6

2-10

Hardware Installation

AMD K6 CPU Core

PR2-166 166MHz = 2.5x 66MHz ON ON OFF 2-3 & 1-2 & 1-2
PR2-200 200MHz = 3x 66MHz OFF ON OFF 2-3 & 1-2 & 1-2
PR2-233 233MHz = 3.5x 66MHz OFF OFF OFF 2-3 & 1-2 & 1-2
PR2-266 266MHz= 4x 66MHz ON OFF ON 2-3 & 1-2 & 1-2
PR2-300 300MHz= 4.5x 66MHz ON ON ON 2-3 & 1-2 & 1-2

Cyrix 6x86
& 6x86L

P150+ 120MHz = 2x 60MHz ON OFF OFF 1-2 & 2-3 & 1-2
P166+ 133MHz = 2x 66MHz ON OFF OFF 2-3 & 1-2 & 1-2
P200+ 150MHz = 2x 75MHz ON OFF OFF 1-2 & 2-3 & 2-3

Cyrix M2 CPU Core

MX-PR166 150MHz = 2.5x 60MHz ON ON OFF 1-2 & 2-3 & 1-2
MX-PR200 166MHz =

MX-PR233 200MHz =

MX-PR266 233MHz = 3.5x 66MHz OFF OFF OFF 2-3 & 1-2 & 1-2

IDT C6 CPU Core

C6-150 150MHz = 2x 75MHz ON OFF OFF 1-2 & 2-3 & 2-3
C6-180 180MHz = 3x 60MHz OFF ON OFF 1-2 & 2-3 & 1-2
C6-200 200MHz = 3x 66MHz OFF ON OFF 2-3 & 1-2 & 1-2

Frequency

CPU Core
Frequency

Frequency

150MHz=

166MHz=3x2x

Frequency

Ratio External

Ratio External

Ratio External

2.5x
2x

Ratio External

Bus Clock

Bus Clock

Bus Clock

66MHz
75MHz
66MHz

83.3MHz

Bus Clock

S1 S2 S3 JP4 & JP5 & JP6

S1 S2 S3 JP4 & JP5 & JP6

S1 S2 S3 JP4 & JP5 & JP6

ONONON

OFFONON

S1 S2 S3 JP4 & JP5 & JP6

OFF

OFF

OFF

2-3 & 1-2 & 1-2

OFF

1-2 & 2-3 & 2-3

OFF

2-3 & 1-2 & 1-2

OFF

2-3 & 1-2 & 2-3

Note: Cyrix 6x86 and AMD K5 CPU use P-rating for the
reference of CPU benchmark compared with INTEL P54C,
their internal core frequency is not exactly equal to P-rating
marked on the CPU. For example, Cyrix P166+ is 133MHz but
performance is almost equal to P54C 166MHz and AMD
PR133 is 100MHz but performance is almost equal to INTEL
P54C 133MHz.

Note: INTEL TX chipset does not support CPU with 50/55MHz
external bus clock, so that P54C 75MHz, Cyrix P120+,P133+
and AMD PR75 are not supported by this mainboard.

2-11

Hardware Installation

2.2.3 Clearing the CMOS

JP14

1-2

2-3

Clear CMOS

Normal operation
(default)
Clear CMOS

You need to clear the CMOS if you forget your
system password. To clear the CMOS, follow
the procedures listed below:

JP14

1 2 3

Normal Operation

(default)

JP14

1 2 3

Clear CMOS

The procedure to clear CMOS:

1. Turn off the system power.

2. Locate JP14 and short pins 2-3 for a few seconds.

3. Return JP14 to its normal setting by shorting pins 1-2.

4. Turn on the system power.

5. Press during bootup to enter the BIOS Setup Utility and specify a new
password, if needed.

2-12

Hardware Installation

(+5V)

2.3 Connectors

2.3.1 Power Cable

A standard baby AT (PS/2) power supply has two cables with six wires on each.
Plug in these cables to the onboard power connector in such a way that all the
black wires are in the center. The power connector is marked as PWR1 on the
system board.

Caution: Make sure that the power supply is
off before connecting or disconnecting the
power cable.

Black wire
(GND)

Red wire

PWR1

2-13

Hardware Installation

3 1 2 4

2.3.2 CPU Fan

Plug in the fan cable to the two-pin fan connector onboard. The fan
connector is marked CPUFAN on the system board. Attach the heatsink and
fan to the CPU. Check its orientation, make sure the air flow go through the
heatsink.

+12V
GND

CPUFAN

2.3.3 PS/2 Mouse

To connect a PS/2 mouse, insert the
PS/2 mouse bracket connector to PS2
MS on the system board. Then plug in
the PS/2 mouse cable to the mouse
port on the bracket.

2-14

Pin

1
2
3
4
5
6

5 6

PS2 MS

Description

MS DATA
NC
GND
+5V
MS CLK
NC

Hardware Installation

1

1

2.3.4 Serial Devices (COM1/COM2)

To support serial devices, insert the serial device connector into the serial port
on the bracket. Plug in the 10-pin flat cable to the appropriate onboard
connectors. The serial port 1 connector is marked as COM1 and the serial
port 2 connector is marked as COM2 on the system board.

2

2

2.3.5 USB Device (optional)

You need a USB bracket to
have your system to support
additional USB device(s). To
attach a USB bracket, simply
insert the bracket cable to the
onboard USB connector marked
as USB.

Pin

1
3
5
7
9

COM2

COM1

1

10

10

Description

V0
D0­D0+
GND
NC

2

9

9

Pin

Description

2

V1

4

D1-

6

D1+

8

GND

10

NC

9 10

USB

2-15

Hardware Installation

1

1

26

2

25

2.3.6 Floppy Drive

Connect the 34-pin floppy drive cable to the floppy drive connector marked as

FDC on the system board.

2

33

34

FDC

2.3.7 Printer

Plug in the 26-pin printer flat cable to the onboard parallel connector
marked as PRINTER on the board.

2-16

PRINTER

Hardware Installation

1

1

2.3.8 IDE Hard Disk and CD ROM

This mainboard supports two 40 pin IDE connectors marked as
IDE1 and IDE2. IDE1 is also known as primary channel and
IDE2 as secondary channel, each channel supports two IDE
devices that makes total of four devices.

In order to work together, the two devices on each channel must
be set differently to master and slave mode, either one can be
hard disk or CDROM. The setting as master or slave mode
depends on the jumper on your IDE device, please refer to your
hard disk and CDROM manual accordingly.

Connect your first IDE hard disk to master mode of the primary
channel. If you have second IDE device to install in your
system, connect it as slave mode on the same channel, and the
third and fourth device can be connected on secondary channel
as master and slave mode respectively.

2

40

39

2

40

39

IDE1 IDE2

Caution: The specification of IDE cable is
maximum 46cm (18 inches), make sure your
cable does not excess this length.

Caution: For better signal quality, it is
recommended to set far end side device to
master mode and follow the suggested
sequence to install your new device . Please
refer to following figure.

2-17

Hardware Installation

(1st)

(2nd)

4

4

4

IDE1 (Primary Channel)

Slave

IDE2 (Secondary Channel)

Slave

(4th)

2.3.9 Hard Disk LED

The HDD LED connector is marked as HDD LED
on the board. This connector is designed for
different type of housing, actually only two pins are
necessary for the LED. If your housing has four pin
connector, simply plug it in. If you have only two pin
connector, please connect to pin 1-2 or pin 3-4
according to the polarity.

+

1
2

-

3

-

+

HDD LED

4-pin connector

2-pin connector

Pin

1
2
3
4

+

-

-

+

HDD LED

at pin 1-2

Master

(3rd)

1
2
3

Master

Description

HDD LED
GND
GND
HDD LED

+

1
2

-

3

-

+

HDD LED

2-pin connector

at pin 3-4

2-18

2.3.10 Panel Connector

+

+++

+

10

20

Hardware Installation

The Panel (multifunction) connector is a 20­pin connector marked as PANEL on the
board. Attach the power LED, keylock,
speaker, reset switch, suspend switch, and
green mode LED connectors to the
corresponding pins as shown in the figure.

Some housings have a five-pin connector for
the keylock and power LED Since power
LED and keylock are aligned together, you
can still use this kind of connector.

Keylock

Power LED

Speaker

KEYLOCK

POWER LED

SPEAKER

SPEAKER

1

11

10 20

GND

GND

RESET

+5V

GND

NC

Suspend SW

Reset

1

11

10 20

PANEL

+5V
GND
GREEN LED
GND
SUSPEND SW
SUSPEND SW
GND
NC
RESET
GND

PANEL

Other housings may have a 12-pin
connector. If your housing has this
type of connector, connect it to PANEL
as shown in the figure. Make sure that
the red wire of the connector is
connected to +5V.

1

11

PANEL

+5V

2-19

Hardware Installation

KB1

Note: If your housing comes with a Turbo switch, you
may use this connector for Suspend switch function.

Note: Pressing the Suspend switch allows you to
manually force the system to suspend mode.
However, this is possible only if the Power
Management function in the BIOS Setup menu is
enabled.

Warning: If you use toggle mode Turbo switch as
Suspend switch, be sure to push it twice to simulate
momentary mode. Otherwise the system may hang or
fail to reboot.

2.3.11 Keyboard

The onboard keyboard connector is a five-pin AT-compatible connector marked as
KB1. The view angle of drawing shown here is from back panel of the housing.

Note: The mini DIN PS/2 keyboard connector
is optional.

2-20

PCB

Hardware Installation

2.3.12 IrDA Connector

Serial port 2 can be configured to support wireless infrared module, with
this module and application software such as Laplink, user can transfer
files to or from laptops, notebooks, PDA and printers. This mainboard
supports IrDA (115Kbps, 1 meter) as well as ASK-IR (19.2Kbps).

Install infrared module onto IrDA
connector and enable infrared function
from BIOS setup, make sure to have
correct orientation when you plug onto
IrDA connector.

Note: Onboard serial port 2 (COM2) will not be
available after IrDA connector is enabled.

IrDA

Pin

1
2
3
4
5
6

1
2
3
4
5
6

Description

+5V
NC
IRRX
GND
IRTX
NC

2-21

Hardware Installation

2.3.13 SB-LINK

SB-LINK is used to connect Creative-compatible

PCI sound card. If you have a Creative-compatible
PCI sound card installed, it is necessary to link the
card to the connector for compatibility issue under
DOS environment.

Pin

1
2
3
4
5
6

1 2

5 6

SB-LINK

Description

GNT#
GND
NC
REQ#
GND
SIRQ#

2-22

Hardware Installation

Bank1

Bank0

168

2.4 Installing the System Memory

This mainboard has four 72 pin SIMM

Pin 1 of

DIMM2

Pin 1 of

DIMM1

Pin 1 of

Pin 1 of

The SIMM supported by this mainboard can be identified by 4 kinds of factors:
I. Size: single side, 1Mx32 (4MB), 4Mx32 (16MB), 16Mx32 (64MB), and double

side, 1Mx32x2 (8MB), 4Mx32x2 (32MB), 16Mx32x2 (128MB).

II. Speed: 60ns or 70ns access time
III. Type: FPM (Fast page mode) or EDO (Extended data output)
IV. Parity: without parity (32 bit wide) or with parity (36 bit wide).

The DIMM supported by this motherboard are always 64-bit wide SDRAM, which
can be identified by following factors:

I. Size: single side, 1Mx64 (8MB), 2Mx64 (16MB), 4Mx64 (32MB), 8Mx64

(64MB), 16Mx64 (128MB), and double side, 1Mx64x2 (16MB), 2Mx64x2
(32MB), 4Mx64x2 (64MB), 8Mx64x2 (128MB).

sockets (Single-in-line Memory Module)
and two 168 pin DIMM socket (Dual-in­line Memory Module) that allow you to
install system memory from minimum
8MB up to maximum 256MB.

Tip: Here is a trick to check if your DIMM is
single-side or double-side -- if there are traces
connected to golden finger pin 114 and pin 129 of
the DIMM, the DIMM is probably double-side;
otherwise, it is single-side. Following figure is for
your reference.

Pin 129

Pin 114

2-23

Hardware Installation

II. Speed: normally marked as -12, which means the clock cycle time is 12ns

and maximum clock of this SDRAM is 83MHz. Sometimes you can also find
the SDRAM marked as -67, which means maximum clock is 67MHz.

III. Buffered and non-buffered: This motherboard supports non-buffered DIMMs.

You can identify non-buffered DIMMs and buffered DIMMs according to the
position of the notch, following figure is for your reference:

Reserved

non-buffered

buffered

Because the positions are different, only non-buffered DIMMs can be inserted into

the DIMM sockets on this motherboard. Although most of DIMMs on current
market are non-buffered, we still recommand you to ask your dealer for the
correct type.

IV. 2-clock and 4-clock signals: Although both of 2-clock and 4-clock signals

are supported by this motherboard, we strongly recommand you to choose 4­clock SDRAM in consideration of reliability.

Tip: To identify 2-clock and 4-clock SDRAM, you
may check if there are traces connected to golden
finger pin 79 and pin 163 of the SDRAM. If there
are traces, the SDRAM is probably 4-clock;
Otherewise, it is 2-clock.

V. Parity: This motherboard supports standard 64 bit wide (without parity)

SDRAM.

Because Pentium CPU has 64 bit bus width, the SIMM sockets are arranged in
two banks of two sockets each, they are Bank0 and Bank1. Both SIMMs in each
bank must be in the same size and type. It is allowed to have different speed and
type in different bank, for example, 70ns FPM in one bank and 60ns EDO in
another bank, in such case, each bank is independently optimized for maximum
performance. The memory timing requires at least 70ns fast page mode DRAM
chip, but for optimum performance, 60ns EDO DRAM is recommended.

2-24

Warning: The default memory timing setting is 60ns to

obtain the optimal performance. Because of the
specification limitation, 70ns SIMM is recommended to
be used only for CPU external clock 60MHz.

Hardware Installation

There is no jumper setting required for the memory size or type. It is
automatically detected by the system BIOS. You can use any single side SIMM
and DIMM combination list below for BANK0/BANK1 or DIMM socket, and the
total memory size is to add them together. Note that because TX chipset

limitation, the maximum is only 256MB.

SIMM1 SIMM2 Subtotal of

Bank0

None None 0MB None None 0MB
4MB 4MB 8MB 4MB 4MB 8MB
8MB 8MB 16MB 8MB 8MB 16MB
16MB 16MB 32MB 16MB 16MB 32MB
32MB 32MB 64MB 32MB 32MB 64MB
64MB 64MB 128MB 64MB 64MB 128MB
128MB 128MB 256MB 128MB 128MB 256MB

DIMM1 Size of DIMM1 DIMM2 Size of DIMM2

None 0MB None 0MB
8MB 8MB 8MB 8MB
16MB 16MB 16MB 16MB
32MB 32MB 32MB 32MB
64MB 64MB 64MB 64MB
128MB 128MB 128MB 128MB
256MB 256MB 256MB 256MB

SIMM3 SIMM4 Subtotal of

Bank1

Total Memory Size = Subtotal of Bank0 + Subtotal of Bank1
+ Size of DIMM1 + Size of DIMM2

For double side memory module, there is one limitation. This mainboard supports
only 4 RAS# (Row address latch) signals for DRAM control. They can only be
occupied by one DRAM module, they can not be shared. The simple rule is: If
double side module at either Bank0 or DIMM1, the other must be empty. If
you use at DIMM1, Bank0 must be empty. Bank1 and DIMM2 have the same
limitation.

2-25

Hardware Installation

Double side module at either Bank0 or
DIMM1, the other must be empty.

Double side module at either Bank1 or
DIMM2, theother must beempty.

Following table explains more about the RAS limitation. You can see that Bank0
1st side and DIMM1 2nd side use the same RAS0#, and Bank0 2nd side and
DIMM1 1st side use the same RAS1#. If you are using single side SIMM at Bank0
and single side DIMM at DIMM1, it should be no problem. But only one double
side DIMM or double side SIMM can be at Bank0 or DIMM1.

RAS0#
RAS1#
RAS2#
RAS3#

Bank0
1st
side

X X

Bank0
2nd
side

X X

Bank1
1st
side

X X

Bank1
2nd
side

X X

DIMM1
1st
side

DIMM1
2nd
side

DIMM2
1st
side

DIMM2
2nd
side

Caution: Make sure that you install the same SIMM type and
size for each bank.

Caution: There are some old DIMMs made by EDO or FPM
memory chip, they can only accept 5V power and probably can
not fit into the DIMM socket, make sure you have 3.3V true
SDRAM DIMM before your insert it.

Tip: If you have DIMM made by 3V EDO, it is possible that TX
chipset can support it. But because it is so rare, the only 3V
EDO DIMM had been tested by this mainboard is Micron
MT4LC2M8E7DJ-6.

Warning: Do not use SIMM and SDRAM DIMM together unless
you have 5V tolerance SDRAM (such as Samsung or TI). The
FPM/EDO operate at 5V while SDRAM operates at 3.3V. If you
combine them together the system will temporary work fine;
however after a few months, the SDRAM 3.3V data input will be
damaged by 5V FPM/EDO data output line.

2-26

Hardware Installation

There is an important parameter affects SDRAM performance, CAS Latency Time.
It is similar as CAS Access Time of EDO DRAM and is calculated as number of
clock state. The SDRAM that AOpen had tested are listed below. If your SDRAM
has unstable problem, go into BIOS "Chipset Features Setup", change CAS
Latency Time to 3 clocks.

Manufacturer Model Suggested CAS

Latency Time

Samsung KM416511220AT-G12 2 Yes
NEC D4S16162G5-A12-7JF 2 No
Hitachi HM5216805TT10 2 No
Fujitsu 81117822A-100FN 2 No
TI TMX626812DGE-12 2 Yes
TI TMS626812DGE-15 3 Yes
TI TMS626162DGE-15 3 Yes
TI TMS626162DGE-M67 3 Yes

5V Tolerance

The driving capability of new generation chipset is limited because the lack of
memory buffer (to improve performance). This makes DRAM chip count an
important factor to be taking into consideration when you install SIMM/DIMM.
Unfortunately, there is no way that BIOS can identified the correct chip count, you
need to calculate the chip count by yourself. The simple rule is: By visual
inspection, use only SIMM with chip count less than 24 chips, and use only DIMM
which is less than 16 chips.

Warning: Do not install any SIMM that contains more than 24
chips. SIMMs contain more than 24 chips exceed the chipset
driving specification. Doing so may result in unstable system
behavior.

Warning: Although Intel TX chipset supports x4 SDRAM chip.
Due to loading issue, it is not recommended to use this kind of
SDRAM.

Tip: The SIMM/DIMM chip count can be calculated by following
example:

1. For 32 bit non-parity SIMM using 1M by 4 bit DRAM chip,
32/4=8 chips.

2. For 36 bit parity SIMM using 1M by 4 bit DRAM chip,
36/4=9 chips.

3. For 36 bit parity SIMM using 1M by 4 bit and 1M by 1 bit
DRAM, the chip count will be 8 data chips(8= 32/4) plus 4

2-27

Hardware Installation

parity chips(4=4/1), total is 12 chips.

4. For 64 bit DIMM using 1M by 16 bit SDRAM, the chip count
is 64/16=4 chips.

Following table list the recommended DRAM combinations of SIMM and DIMM:

SIMM
Data chip

1M by 4 None 1Mx32 x1 8 4MB Yes
1M by 4 None 1Mx32 x2 16 8MB Yes
1M by 4 1M by 1 1Mx36 x1 12 4MB Yes
1M by 4 1M by 4 1Mx36 x1 9 4MB Yes
1M by 4 1M by 4 1Mx36 x2 18 8MB Yes
1M by 16 None 1Mx32 x1 2 4MB Yes
1M by 16 None 1Mx32 x2 4 8MB Yes
1M by 16 1M by 4 1Mx36 x1 3 4MB Yes
1M by 16 1M by 4 1Mx36 x2 6 8MB Yes
4M by 4 None 4Mx32 x1 8 16MB Yes
4M by 4 None 4Mx32 x2 16 32MB Yes
4M by 4 4M by 1 4Mx36 x1 12 16MB Yes
4M by 4 4M by 1 4Mx36 x2 24 32MB Yes

SIMM
Data chip

16M by 4 None 16Mx32 x1 8 64MB Yes, but not

16M by 4 None 16Mx32 x2 16 128MB Yes, but not

16M by 4 16M by 4 16Mx36 x1 9 64MB Yes, but not

16M by 4 16M by 4 16Mx36 x2 18 128MB Yes, but not

SIMM
Parity chip

SIMM
Parity chip

Bit size
per side

Bit size
per side

Single/
Double
side

Single/
Double
side

Chip
count

Chip
count

SIMM
size

SIMM
size

Recommended

Recommended

tested.

tested.

tested.

tested.

DIMM
Data chip

1M by 16 1Mx64 x1 4 8MB Yes
1M by 16 1Mx64 x2 8 16MB Yes
2M by 8 2Mx64 x1 8 16MB Yes
2M by 8 2Mx64 x2 16 32MB Yes

Bit size per
side

Single/
Double side

Chip
count

DIMM size Recommended

2-28

Hardware Installation

DIMM
Data chip

2M by 32 2Mx64 x1 2 16MB Yes, but not tested.
2M by 32 2Mx64 x2 4 32MB Yes, but not tested.
4M by 16 4Mx64 x1 4 32MB Yes, but not tested.
4M by 16 4Mx64 x2 8 64MB Yes, but not tested.
8M by 8 8Mx64 x1 8 64MB Yes, but not tested.
8M by 8 8Mx64 x2 16 128MB Yes, but not tested.

Bit size per
side

Single/
Double side

Chip
count

DIMM size Recommended

Warning: 64MB SIMMs using 16M by 4 bit chip (64M bit
technology) are not available in the market and are not
formally tested by AOpen quality test department yet.
However they are supported by design specification from
Intel and they will be tested as soon as they are
available. Note that 64MB SIMMs using 16M by 1 bit
chip (16M bit technology) have chip count exceed 24 and
are strongly not recommended.

Tip: 8 bit = 1 byte, 32 bit = 4 byte. The SIMM size is
represented by number of data byte (whether with or
without parity), for example, the size of single side SIMM
using 1M by 4 bit chip is 1Mx32 bit, that is, 1M x 4 byte=
4MB. For double side SIMM, simply multiply it by 2, that
is, 8MB.

2-29

Hardware Installation

Following table are possible DRAM combinations that is NOT recommended:

SIMM
Data chip

1M by 1 None 1Mx32 x1 32 4MB No
1M by 1 1M by 1 1Mx36 x1 36 4MB No
1M by 4 1M by 1 1Mx36 x2 24 8MB No
4M by 1 None 4Mx32 x1 32 16MB No
4M by 1 4M by 1 4Mx36 x1 36 16MB No
16M by 1 None 16Mx32 x1 32 64MB No
16M by 1 16M by 1 16Mx36 x1 36 64MB No

DIMM
Data chip

4M by 4 4Mx64 x1 16 32MB No
4M by 4 4Mx64 x2 32 64MB No
16M by 4 16Mx64 x1 16 128MB No
16M by 4 16Mx64 x2 32 256MB No

SIMM
Parity chip

Bit size per
side

Bit size
per side

Single/
Double side

Single/
Double
side

Chip
count

Chip
count

SIMM
size

DIMM size Recommended

Recommended

Memory error checking is supported by parity check. To use parity check you
need 36 bit SIMM (32 bit data + 4 bit parity), which are automatically detected by
BIOS.

Tip: The parity mode uses 1 parity bit for each byte,
normally it is even parity mode, that is, each time the
memory data is updated, parity bit will be adjusted to
have even count "1" for each byte. When next time, if
memory is read with odd number of "1", the parity error
is occurred and this is called single bit error detection.

2-30