SBC8251 Motherboard Settings and Configuration

Processor	Cyrix/Pentium
Processor Speed	75/90/100/120/133/150/166/180/200MHz
Chip Set	Intel
Video Chip Set	Chips and Technology
Maximum Onboard Memory	64MB
Maximum Video Memory	2MB
Cache	256/512KB
BIOS	Unidentified
Dimensions	185mm x 122mm
I/O Options	Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, PS/2 mouse interface, serial ports (2), VGA port, PC/104 connectors (2)
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
PS/2 mouse port	CN1	Internal buzzer	JP12/pins 1- 3
VGA port	CN2	Power LED & keylock	JP12/pins 2 - 10
Serial port 1	CN3	External speaker	JP12/pins 4 - 7
Parallel port	CN4	Green PC connector	JP12/pins 5 & 9
Floppy drive interface	CN5	Reset switch	JP12/pins 11 & 12
IDE interface	CN6	IDE interface LED	JP12/pins 17 & 18
Serial port 2	CN7	Watchdog timer	JP3/pins 19 & 20
Power connector	J1	PC/104 connector	P1
Power connector	J3	PC/104 connector	P2
Keyboard, PS/2 mouse	J4

USER CONFIGURABLE SETTINGS
Function		Label	Position
»	Factory configured - do not alter	J2	Unidentified
»	SHFCLK normal operation	JP5	Pins 2 & 3 closed
	SHFCLK inverted	JP5	Pins 1 & 2 closed
	Flash BIOS write protect disabled	JP7	Pins 1 & 2 closed
	Flash BIOS write protect enabled	JP7	Pins 2 & 3 closed
»	CMOS memory normal operation	JP8	Pins 2 & 3 closed
	CMOS memory clear	JP8	Pins 1 & 2 closed
	Cache type select write back	JP10	Pins 2 & 3 closed
	Cache type select write through	JP10	Pins 1 & 2 closed
	System clock = PCI clock/4	JP13	Open
	System clock = PCI clock/3	JP13	Closed

SIMM CONFIGURATION
Size	Bank 0
8MB	(2) 1M x 36
16MB	(2) 2M x 36
32MB	(2) 4M x 36
64MB	(2) 8M x 36

SIMM REFRESH RATE CONFIGURATION
Setting	JP16/pins 1 & 2
60MHz	Closed
66MHz	Open

CACHE CONFIGURATION

Note: The location of the cache is unidentified.

CACHE JUMPER CONFIGURATION
Size	JP16
256KB	Pins 3 & 4 closed
512KB	Pins 5 & 6 closed

VIDEO MEMORY CONFIGURATION

Note: The location of the video memory is unidentified.

CPU BUS SPEED SELECTION
Speed	JP18
50MHz	Pins 1 & 2, 3 & 4 closed
55MHz	Open
60MHz	Pins 3 & 4 closed
66MHz	Pins 1 & 2 closed

CPU BUS/CORE SELECTION
Bus/Core	JP16
2/5	Pins 7 & 8, 9 & 10 closed
1/3	Pins 9 & 10 closed
1/2	Pins 7 & 8closed
2/3	Open

CPU TYPE SELECTION
Type	JP9
Cyrix	Pins 1 & 2 closed
Intel	Pins 2 & 3 closed

CPU VOLTAGE SELECTION (SINGLE)
Voltage	JP1
3.3v	Pins 1 & 2 closed
3.6v	Pins 2 & 3 closed

CPU VOLTAGE SELECTION (DUAL)
Voltage	JP2
2.7v	Pins 4 & 6 closed
2.9v	Pins 2 & 4 closed
3.3v	Pins 1 & 3 closed
3.45v	Pins 3 & 5 closed

SERIAL PORT 2 SELECTION
Setting	JP11	JP17
RS232	5 & 6	3 & 5, 4 & 6, 9 & 11, 10 & 12
RS422	3 & 4	1 & 3, 2 & 4, 7 & 9, 8 & 10
RS485	1 & 2	1 & 3, 2 & 4, 7 & 9, 8 & 10
Note: Pins designated should be in the closed position.

LCD PANEL INTERFACE SELECTION
Setting	JP6	JP15
3.3v panel	Closed	Pins 1 & 2 closed
5v panel	Open	Pins 2 & 3 closed

LCD PANEL TYPE SELECTION

Note: Pins 9 & 10, 11 & 12, 13 & 14, 15 & 16 on JP3 are used to select up to 16 typed of LED BIOS.

DISK ON CHIP ADDRESS SELECTION
Setting	JP3
C0000 – C7FFF	Pins 1 & 2 closed
C8000 – CFFFF	Pins 3 & 4 closed
D0000 – D7FFF	Pins 5 & 6 closed
D8000 – DFFFF	Pins 7 & 8 closed