486-EL Motherboard Settings and Configuration

Processor	80486SX/80486DX/80486DX2/80486DX4
Processor Speed	25/33/50(internal)/66(internal)/75(internal)/100(internal)MHz
Chip Set	OPTI
Max. Onboard DRAM	16MB
Cache	8KB (on EDRAM modules)
BIOS	AMI
Dimensions	250mm x 220mm
I/O Options	32-bit VESA local bus slots (3), green PC connector
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
External battery	JP2	Reset switch	JP27
Green PC connector	JP3	Power LED & keylock	JP28
Turbo LED	JP25	Speaker	JP30
Turbo switch	JP26	32-bit VESA local bus slots	SL1 - SL3

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	CMOS memory normal operation	JP1	pins 2 & 3 closed
	CMOS memory clear	JP1	pins 1 & 2 closed
	Green PC IRQ select IRQ10	JP23	pins 1 & 2 closed
	Green PC IRQ select IRQ11	JP23	pins 2 & 3 closed
	Green PC timer select short time (1.5 minutes)	JP29	Closed
	Green PC timer select long time (8 minutes)	JP29	Open

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2	Bank 3
4MB	4MB	NONE	NONE	NONE
8MB	4MB	4MB	NONE	NONE
8MB	8MB	NONE	NONE	NONE
12MB	4MB	4MB	4MB	NONE
16MB	4MB	4MB	4MB	4MB
16MB	8MB	NONE	8MB	NONE
Note: This board is only compatible with EDRAM modules.

CACHE CONFIGURATION
Memory installed	Cache installed
4MB	2KB
8MB	4KB
8MB	4KB
12MB	6KB
16MB	8KB
16MB	8KB
Note: Cache is located on EDRAM modules.

CPU TYPE CONFIGURATION
Type	JP19	JP20	JP21
80486SX	Open	pins 1 & 2 closed	pins 1 & 2 closed
80486DX	Closed	pins 2 & 3 closed	pins 2 & 3 closed
80486DX2	Closed	pins 2 & 3 closed	pins 2 & 3 closed
80486DX4	Closed	pins 2 & 3 closed	pins 2 & 3 closed

CPU SPEED CONFIGURATION
Speed	JP9	JP10	JP36
25MHz	Open	Closed	pins 1 & 2 closed
33MHz	Closed	Open	pins 1 & 2 closed
50iMHz	Open	Closed	pins 1 & 2 closed
66iMHz	Closed	Open	pins 1 & 2 closed
75iMHz	Open	Closed	pins 2 & 3 closed
100iMHz	Closed	Open	pins 1 & 2 closed

CPU SPEED CONFIGURATION (80486DX4 ONLY)
Speed	JP35
2x	pins 1 & 2 closed
2.5x	pins 2 & 3 closed
3x	Open