MSI MS-6785 User manual

1-1
Getting Started
Chapter 1. Getting
Started
Getting Started
Thank you for purchasing the MS-6785 v1.X Micro ATX
mainboard. The MS-6785 is based on SiS®648FX &SiS®963
chipsets for optimal system efficiency. Designed to fit the ad-
vanced Intel®Pentium®4 processors in the 478 pin package, the
MS-6785 delivers a high performance and professional desktop
platform solution.

1-2
MS-6785 M-ATX Mainboard
Mainboard Specifications
CPU
hSocket478forP4processorswith400/533/800MHz(100/133/200MHzQDIR).
hCore frequency up to 3.2GHz.
Chipset
hSiS®648FX (839pinBGA)
- Supports Intel®Pentium®4 processors with data transfer rate up to 800
MHz.
- Supports 64-bit high performance DDR400/333/266 memory controller.
- Supports AGP 8X/4X interface at 0.8v or 4x at 1.5v with fast write
transaction.
- Supports bi-directional 16-bit data bus with 1GHz bandwidth MuTIOL.
hSiS®963 (371pinBGA)
- Supports high throughput SiS MuTIOL 1GHz interconnecting to SiS®963
mediaI/O.
- Supports Dual-IDE ATA 66/100/133.
- Integrated Direct Sound AC97 audio.
- Low pin count interface for SIO.
- Advanced power management and PC2001 compliance.
- High speed USB 2.0 controller, 480Mb/s.
MainMemory
hSupports four memory banks using two 184-pin DDR DIMMs.
hSupports up to 2GB PC3200/2700/2100DDR SDRAMs.
hSupports 2.5v DDR SDRAM.
Slots
hOne AGP (Accelerated Graphics Port) slot
- Supports AGP 3.0 4x/8x.
hThree 32-bit PCI bus slots.
- Support 3.3v/5v PCI bus interface.
- The second PCI slot in BLUE supports 2 master devices.
On-BoardIDE
hDual IDE controllers integrated in SiS 963.
hSupports P/O, Bus Master, Ultra DMA66/100/133 operation.
hCan connect up to four IDE devices.

1-3
Getting Started
On-BoardPeripherals
hOn-Board Peripherals include:
- One floppy port supports 2 FDDs with 360K, 720K, 1.2M, 1.44M and
2.88Mbytes
- One serial port (COM A)
- One parallel port supports SPP/EPP/ECP mode (Optional)
- One RJ-45 LAN port
- Vertical audio ports
- One RCA_SPDIF In & one RCA_SPDIF Out
- Three 1394 ports [Rear x 2 (6 / 4 pins) + Front x 1 (6 pins)]
- Six USB 2.0 ports (Rear * 2/ Front * 4)
OnboardIEEE1394
hIntegrated in SiS®963.
hAgere FW803 PHY.
Audio
hS/W C-Media 9739A 5.1 channel with SPDIF in/out.
LAN
hVIA®VT6103LANcontroller.
BIOS
hThe mainboard BIOS provides “Plug & Play” BIOS which detects the pe-
ripheral devices and expansion cards of the board automatically.
hThe mainboard provides a Desktop Management Interface (DMI) function
which records your mainboard specifications.
Dimension
hMicro ATX Form Factor: 24.0 cm x 24.5 cm.
Mounting
h6 mounting holes.

1-4
MS-6785 M-ATX Mainboard
Mainboard Layout
MS-6785v1.X Micro ATX Mainboard
DDR1
DDR2
AGP Slot
SiS
648FX
Top : mouse
Bottom:keyboard
T: RJ45 LAN jack
B: USB ports
JSPDIF1
J9
CN8
1394port
Mini1394 port
JVEDIO1
Codec
VIA
VT6103
AGERE
FW803
BATT
+
BIOS
Winbond
83697HF
SiS
963
IDE1
IDE2
FDD1
PCI Slot1
PCI Slot2
PCI Slot3
JAUDIO1
CPUFAN1
JPW1
JLPT1
ATX
PowerSupply
JUSB1
F_P1
JBAT1
Line-Out
Line-Out
Line-Out
Line-Out
Line-Out
Line-Out
T:Mic
B:Line-In
T:SPDIF in
B:SPDIF out

2-1
Hardware Setup
Chapter 2. Hardware
Setup
Hardware Setup
This chapter provides you with the information about hard-
ware setup procedures. While doing the installation, be careful
in holding the components and follow the installation procedures.
For some components, if you install in the wrong orientation,
the components will not work properly.
Use a grounded wrist strap before handling computer
components. Static electricity may damage the components.

2-2
MS-6785 M-ATX Mainboard
Quick Components Guide
CPU, p.2-3
JPW1,p.2-9
Back Panel
I/O, p.2-10
CPUFAN1, p.2-17
DIMM1/2,
p.2-7
FDD1,
p.2-15
IDE2,
p.2-16
JUSB1,
p.2-19
F_P1,p.2-18JAUDIO1,p.2-22
JVIDEO1,p.2-18
PCI Slots,
p.2-25
AGP Slot,p.2-25
JSPDIF1,p.2-21
JBAT1,p.2-24
J7,p.2-23
CONN1,
p.2-9
J9,p.2-20
IDE1,
p.2-16

2-3
Hardware Setup
Central Processing Unit: CPU
CPU Core Speed Derivation Procedure
If CPU Clock = 100MHz
Core/Bus ratio = 14
then CPU core speed = Host Clock x Core/Bus ratio
= 100MHz x 14
= 1.4 GHz
MSI Reminds You...
Overheating
Overheating will seriously damage the CPU and system, al-
ways make sure the cooling fan can work properly to protect
the CPU from overheating.
Replacing the CPU
While replacing the CPU, always turn off the ATX power sup-
ply or unplug the power supply’s power cord from grounded
outlet first to ensure the safety of CPU.
Overclocking
This motherboard is designed to support overclocking. However,
please make sure your components are able to tolerate such
abnormal setting, while doing overclocking. Any attempt to
operate beyond product specifications is not recommended. We
do not guarantee the damages or risks caused by inadequate
operation or beyond product specifications.
The mainboard supports Intel®Pentium®4 processors in the 478 pin
package. The mainboard uses a CPU socket called PGA478 for easy CPU
installation. When you are installing the CPU, make sure the CPU has a heat
sink and a cooling fan attached on the top to prevent overheating. If you
do not find the heat sink and cooling fan, contact your dealer to purchase and
install them before turning on the computer.

2-4
MS-6785 M-ATX Mainboard
1. Please turn off the power and
unplug the power cord before
installing the CPU.
2. Pull the lever sideways away
from the socket. Make sure to
raise the lever up to a 90-de-
gree angle.
3. Look for the gold arrow. The
gold arrow should point to-
wards the lever pivot. The
CPU can only fit in the cor-
rect orientation.
4. If the CPU is correctly
installed, the pins should be
completely embedded into the
socket and can not be seen.
Please note that any violation
of the correct installation pro-
cedures may cause permanent
damages to your mainboard.
5. Press the CPU down firmly
into the socket and close the
lever. As the CPU is likely to
move while the lever is being
closed, always close the lever
with your fingers pressing
tightly on top of the CPU to
make sure the CPU is prop-
erly and completely embed-
ded into the socket.
CPU Installation Procedures for Socket 478
Open Lever
90 degree
Sliding
Plate
Close
Lever
Press down
the CPU
Gold arrow
Gold arrow
Gold arrow
Correct CPU placement
Incorrect CPU placement
X
O

2-5
Hardware Setup
Installing the CPU Fan
As processor technology pushes to faster speeds and higher performance,
thermal management becomes increasingly important. To dissipate heat, you
need to attach the CPU cooling fan and heatsink on top of the CPU. Follow the
instructions below to install the Heatsink/Fan:
2. Position the heatsink onto the reten-
tion mechanism.
1. Locate the CPU and its retention
mechanism on the motherboard.
3. Mount the fan on top of the heatsink.
Press down the fan until its four clips
get wedged in the holes of the reten-
tion mechanism.
4. Press the two levers down to fasten
the fan. Each lever can be pressed
down in only ONE direction.
retention mechanism
levers

2-6
MS-6785 M-ATX Mainboard
5. Connect the fan power cable from the mounted fan to the 3-pin fan power connector
on the board.
fan power cable
NOTES

2-7
Hardware Setup
The mainboard provides 2 slots for 184-pin DDR SDRAM DIMM
(Double In-Line Memory Module) modules and supports the memory size up
to 2GB. You can install PC2700/DDR333, PC2100/DDR266 or PC1600/
DDR200 modules on the DDR DIMM slots (DIMM 1~2).
Memory
DDR DIMM Slots
(DIMM 1~2)
Introduction to DDR SDRAM
DDR (Double Data Rate) SDRAM is similar to conventional SDRAM,
but doubles the rate by transferring data twice per cycle. It uses 2.5 volts as
opposed to 3.3 volts used in SDR SDRAM, and requires 184-pin DIMM mod-
ules rather than 168-pin DIMM modules used by SDR SDRAM. High memory
bandwidth makes DDR an ideal solution for high performance PC, worksta-
tions and servers.

2-8
MS-6785 M-ATX Mainboard
DIMM Module Combination
Install at least one DIMM module on the slots. Memory modules can be
installed on the slots in any order. You can install either single- or double-
sided modules to meet your own needs.
Memory modules can be installed in any combination as follows:
Installing DDR Modules
1. The DDR DIMM has only one notch on the center of module. The mod-
ule will only fit in the right orientation.
2. Insert the DIMM memory module vertically into the DIMM slot. Then
push it in until the golden finger on the memory module is deeply inserted
in the socket.
3. The plastic clip at each side of the DIMM slot will automatically close.
S: Single Side D: Double Side
Slot Memory Module Total Memory
DIMM 1
(Bank 0 & 1) S/D 64MB~1GB
DIMM 2
(Bank 2 & 3) S/D 64MB~1GB
Maximum System Memory Supported 64MB~2GB
MSI Reminds You...
You can barely see the golden finger if the module is properly
inserted in the socket.
Volt Notch

2-9
Hardware Setup
Power Supply
The mainboard supports ATX power supply for the power system. Be-
fore inserting the power supply connector, always make sure that all compo-
nents are installed properly to ensure that no damage will be caused.
ATX 20-Pin Power Connector: CONN1
This connector allows you to connect to an ATX power supply. To con-
nect to the ATX power supply, make sure the plug of the power supply is
inserted in the proper orientation and the pins are aligned. Then push down
the power supply firmly into the connector.
ATX 12V Power Connector: JPW1
This 12V power connector is used to provide power to the CPU.
CONN1
10
1
20
11
PIN SIGNAL
11 3.3V
12 -12V
13 GND
14 PS_ON
15 GND
16 GND
17 GND
18 -5V
19 5V
20 5V
PIN SIGNAL
1 3.3V
2 3.3V
3 GND
45V
5 GND
65V
7 GND
8 PW_OK
9 5V_SB
10 12V
CONN1 Pin Definition
PIN SIGNAL
1 GND
2 GND
3 12V
4 12V
JPW1 Pin Definition
JPW1
1
3 4
2

2-10
MS-6785 M-ATX Mainboard
The back panel provides the following connectors:
Back Panel
Mouse/Keyboard Connector
The mainboard provides a standard PS/2®mouse/keyboard mini DIN
connector for attaching a PS/2®mouse/keyboard. You can plug a PS/2®mouse/
keyboard directly into this connector. The connector location and pin assign-
ments are as follows:
PS/2 Mouse/Keyboard
(6-pin Female)
21
3
4
5
6PIN SIGNAL DESCRIPTION
1 Mouse/Keyboard Data Mouse/Keyboard data
2 NC No connection
3 GND Ground
4 VCC +5V
5 Mouse/Keyboard Clock Mouse/Keyboard clock
6 NC No connection
Pin Definition
Keyboard
Mouse
SPDIF-Out
SPDIF-In
USBCOM A
LAN
6 Channel
L-Out
L-In
IEEE1394
Ports
MIC

2-11
Hardware Setup
SPDIF Connectors
The SPDIF connectors privided on the back pannel can be used to con-
nect your digital audio equipment.
Serial Port Connector: COM A
The mainboard offers one 9-pin male DIN connectors as serial port COM
A. This port is a 16550A high speed communication port that sends/receives
16 bytes FIFOs. You can attach a serial mouse or other serial devices directly
to this connector.
PIN SIGNAL DESCRIPTION
1 DCD Data Carry Detect
2 SIN Serial In or Receive Data
3 SOUT Serial Out or Transmit Data
4 DTR Data Terminal Ready)
5 GND Ground
6 DSR Data Set Ready
7 RTS Request To Send
8 CTS Clear To Send
9 RI Ring Indicate
Pin Definition
9-Pin Male DIN Connector
1 2 3 4 5
6 7 8 9
SPDIF
IN
SPDIF
OUT

2-12
MS-6785 M-ATX Mainboard
Parallel Port Connector: LPT1
The mainboard provides a 25-pin female centronic connector as LPT. A
parallel port is a standard printer port that supports Enhanced Parallel Port
(EPP) and Extended Capabilities Parallel Port (ECP) mode.
13 1
14
25
PIN SIGNAL DESCRIPTION
1 STROBE Strobe
2 DATA0 Data0
3 DATA1 Data1
4 DATA2 Data2
5 DATA3 Data3
6 DATA4 Data4
7 DATA5 Data5
8 DATA6 Data6
9 DATA7 Data7
10 ACK# Acknowledge
11 BUSY Busy
12 PE Paper End
13 SELECT Select
14 AUTO FEED# Automatic Feed
15 ERR# Error
16 INIT# Initialize Printer
17 SLIN# Select In
18 GND Ground
19 GND Ground
20 GND Ground
21 GND Ground
22 GND Ground
23 GND Ground
24 GND Ground
25 GND Ground
Pin Definition

2-13
Hardware Setup
USB Connectors
The mainboard provides four UHCI (Universal Host Controller Interface)
Universal Serial Bus roots for attaching USB devices such as keyboard, mouse
or other USB-compatible devices. You can plug USB devices directly into the
connectors.
USB Ports
1 2 3 4
5 6 7 8
PIN SIGNAL DESCRIPTION
1 VCC +5V
2 -Data 0 Negative Data Channel 0
3 +Data0 Positive Data Channel 0
4 GND Ground
5 VCC +5V
6 -Data 1 Negative Data Channel 1
7 +Data 1 Positive Data Channel 1
8 GND Ground
USB Port Description
RJ-45 LAN Jack (Optional)
The mainboard provides one standard RJ-45 jack for connection to Lo-
cal Area Network (LAN). You can connect a network cable to the LAN jack.
Pin Definition
PIN SIGNAL DESCRIPTION
1 TDP Transmit Differential Pair
2 TDN Transmit Differential Pair
3 RDP Receive Differential Pair
4 NC Not Used
5 NC Not Used
6 RDN Receive Differential Pair
7 NC Not Used
8 NC Not Used
RJ-45 LAN Jack

2-14
MS-6785 M-ATX Mainboard
IEEE1394 Ports
The mainboard provides two IEEE 1394 ports. The mini IEEE1394
port is designed for you to connect the IEEE1394 device with external power.
The standard IEEE1394 port connects to IEEE1394 devices without external
power. The IEEE1394 high-speed serial bus complements USB by providing
enhanced PC connectivity for a wide range of devices, including consumer
electronics audio/video (A/V) appliances, storage peripherals, other PCs, and
portable devices.
Audio Port Connectors
Line Out is a connector for Speakers or Headphones. Line In is used for
external CD player, Tape player, or other audio devices. Mic is a connector
for microphones.
MIC
Line-In
Line-Out
(subwoofer speaker)
Line-Out
(rear speakers)
Line-Out
(front speaker)
IEEE1394 Port
(Mini)
IEEE1394 Port
(Standard)

2-15
Hardware Setup
The mainboard provides connectors to connect to FDD, IDE HDD, case,
modem, LAN, USB Ports, IR module and CPU/System/Power Supply FAN.
Floppy Disk Drive Connector: FDD1
The mainboard provides a standard floppy disk drive connector that sup-
ports 360K, 720K, 1.2M, 1.44M and 2.88M floppy disk types.
Connectors
FDD1

2-16
MS-6785 M-ATX Mainboard
Hard Disk Connectors: IDE1 & IDE2
The mainboard has a 32-bit Enhanced PCI IDE and Ultra ATA 33/66/
100/133 controller that provides PIO mode 0~4, Bus Master, and Ultra ATA
33/66/100/133 function. You can connect up to four hard disk drives, CD-
ROM, 120MB Floppy (reserved for future BIOS) and other devices.
The Ultra ATA 133 interface boosts data transfer rates between the com-
puter and the hard drive up to 133 megabytes (MB) per second. The new
interface is one-third faster than earlier record-breaking Ultra ATA/100 tech-
nology and is backwards compatible with the existing Ultra ATA interface.
IDE1 (Primary IDE Connector)
The first hard drive should always be connected to IDE1. IDE1 can
connect a Master and a Slave drive. You must configure second hard
drive to Slave mode by setting the jumper accordingly.
IDE2 (Secondary IDE Connector)
IDE2 can also connect a Master and a Slave drive.
MSI Reminds You...
If you install two hard disks on cable, you must configure the
second drive to Slave mode by setting its jumper. Refer to the
hard disk documentation supplied by hard disk vendors for
jumper setting instructions.
IDE2 IDE1