M520

J1 Power Supply Connector

The power supply connectors are two six-pin male header connectors. Plug the dual connectors from the power directly onto the board connectors.
Most of power supply have two leads. Each lead has six wires. Two of which are black, orient the connectors, so the black wires are in the middle.

Power Supply Connectors
Pin Description Pin Description
1 Power Good 7 Ground
2 + 5V DC 8 Ground
3 + 12V DC 9 - 5V DC
4 - 12V DC 10 + 5V DC
5 Ground 11 + 5 V DC
6 Ground 12 + 5V DC

J2 Keyboard Connector

A standard five-pin female DIN keyboard connector is located at the rear of the board J2.

Keyboard Connector
Pin Description
1 Keyboard Clock
2 Keyboard Data
3 N.C.
4 Ground
5 + 5VDC

Universal Serial Bus Connector

U.S.B. Connector
Pin Description Pin Description
1 +5 VDC 6 +5 VDC
2 DATA - 7 DATA -
3 DATA + 8 DATA +
4 Ground 9 Ground
5 N.C. 10 N.C.

J5 HDD LED Connector

HDD LED Connector
Pin Description
1 5V
2 Active Low

J6 Reset Switch Connector

Attach the Reset switch cable to this connector

Reset Connector
Setting Description
Open Normal Mode
Short Reset System

J7 Internal / External Battery Selectors

Battery Selectors
Description J7
External Battery Pin 1 and pin 4
to connect external battery
Internal Battery Pin 2-3 short
Clear CMOS Pin 3-4 short

J8 Keylock & Power LED Connector

J8 is a keylock connector that enables and disables the keyboard and the Power-LED on the case.

Keylock & Power LED Connector
Pin Description
1 LED Output
2 N.C.
3 Ground
4 Keylock

J9 Speaker Connector

Attach the system speaker to connector J9.

Speaker Connectors
Pin Description
1 DATA Out
2 N.C.
3 Ground
4 + 5V

JP4 Flash ROM Voltage Selector

The mainboard can uses two types of Flash ROM 5 volt and 12 volt. Set the mainboard for either type with jumper JP4. You can update both types with new BIOS files as they come available.

Flash ROM Voltage Selector
Description JP4
12 volt Flash ROM short
EPROM and 5 volt Flash ROM open

JP5 AT Bus Clock Selector

AT Bus Clock Selector
Description JP5
PCI Clock/4 Pin 1-2 short (default)
PCI Clock/3 Pin 2-3 short

NOTE:
CPU Ex. Speed=60MHz or 66MHz, JP 5 set to 1-2
CPU Ex. Speed=50MHz, JP 5 set to 2-3

JP6 Sleep Switch Connector

Attach the sleep switch cable to this connector

Sleep Switch Connector
Description JP6
Normal Mode Open
Sleep Mode On Pin 1-2 short

JP7 DIMM Socket Voltage Selectors

DIMM Socket Voltage Selectors
Voltage Selectors JP7
3.3 Volt Pin 2-3 short
5.0 Volt Pin 1-2 short (default)

NOTE:
All synchronous DRAM (SDRAM) JP7 must be set to 3.3 V position.

JP10, JP11 CPU Speed Selectors

The mainboard has a clock generator that lets you choose the CPU frequency by settings jumpers JP10, JP11. You can set the CPU speed to 50 / 60 MHz or 66 MHz as shown below.

CPU Speed Selectors
Jumpers 66 MHz 60 MHz 50 MHz {55 MHz
(CMA8860-55)		 /75 MHz}
(CMA8860-75)
JP10 Short Open Short Open Open
JP11 Open Short Short Open Open

JP12, JP13 - CPU Internal Clock Speed Selectors

CPU Internal Clock Speed Selectors
Intel Cyrix AMD JP12 JP13
x 2.0 x 2.0 Reserved Short Open
x 1.5 Reserved x 1.5 Open Open
x 2.5 Reserved Reserved Short Short
x 3.0 Reserved Reserved Open Short

NOTE:
CPU Internal Clock Speed = (External Input Clock) x (table list) factor.

JP14 CPU Voltage Regulator Output Selectors

CPU Voltage Regulator Output Selectors
Description JP14
3.3 Volt (STD/VR) Pin 2-3 short
3.5 Volt (VRE) Pin 1-2 short (default)

External Cache Configuration

This mainborad supports a cache module socket you can install pipeline burst SRAM on a cache module in the cache module slot, the cache module size can eirher 256KB or 512KB.

External Cache Configuration
Cache Type Size Data Chip Size Tag Chip Size
Pipeline Burst 256KB 32k32 x 2 pcs 8k8, 16k8 or 32kx8 x 1 pc
512KB 32k32 x 4 pcs 16k8 or 32k8 x 1 pc
512KB 64k32 x 2 pcs 16k8 or 32k8 x 1 pc