386SX/486DX Motherboard Settings and Configuration

Processor	80386DX/CX486DLC/80486SX/80487SX/ODP486SX/80486DX/80486DX2
Processor Speed	25/33/40/50(internal)/50/66(internal)MHz
Chip Set	OPTI
Max. Onboard DRAM	64MB
Cache	64/128/256KB
BIOS	AMI
Dimensions	254mm x 220mm
I/O Options	32-bit VESA local bus slots (2)
NPU Options	80387DX

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	J1	Turbo LED	J5
Speaker	J2	External battery	J6
Turbo switch	J3	32-bit VESA local bus slots	SL1 & SL2
Reset switch	J4

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Turbo switch enabled	J3	Open
	turbo switch disabled	J3	Closed
»	CMOS memory normal operation	J6	pins 2 & 3 closed
	CMOS memory clear	J6	pins 3 & 4 closed
»	Cyrix DLC PQFP CPU disabled	JP4	Closed
	Cyrix DLC PQFP CPU enabled	JP4	Open
»	80386DX/80486DX PQFP CPU disabled	JP15	Closed
	80386DX/80486DX PQFP CPU enabled	JP15	Open
»	Monitor type select color	JP21	Closed
	Monitor type select monochrome	JP21	Open
»	Factory configured - do not alter	JP23	Open
»	VESA card select standard card in SL1	JP24	pins 2 & 3 closed
	VESA card select WD31 or Tekram IDE card (50MHz only)	JP24	pins 1 & 2 closed
»	Battery type select Lithum	JP26	pins 1 & 2 closed
	Battery type select NI-CD	JP26	pins 2 & 3 closed
»	80486DX-50 version select old	JP28	Open
	80486DX-50 version select new	JP28	Closed

DRAM CONFIGURATION
Size	Bank 0	Bank 1
1MB	(4) 256K x 9	NONE
2MB	(4) 256K x 9	(4) 256K x 9
4MB	(4) 1M x 9	NONE
5MB	(4) 256K x 9	(4) 1M x 9
8MB	(4) 1M x 9	(4) 1M x 9
16MB	(4) 4M x 9	NONE
17MB	(4) 256K x 9	(4) 4M x 9
20MB	(4) 1M x 9	(4) 4M x 9
20MB	(4) 4M x 9	(4) 1M x 9
32MB	(4) 4M x 9	(4) 4M x 9
64MB	(4) 16M x 9	NONE

CACHE CONFIGURATION
Size	Bank 0	Bank 1	TAG (U18)	TAG (U19)
64KB	(4) 8K x 8	(4) 8K x 8	(1) 8K x 8	NONE
128KB	(4) 32K x 8	NONE	(1) 8K x 8	NONE
256KB	(4) 32K x 8	(4) 32K x 8	(1) 32K x 8	NONE
256KB	(4) 32K x 8	(4) 32K x 8	(1) 8K x 8	(1) 8K x 8

CACHE JUMPER CONFIGURATION
Size	JP10	JP11	JP16	JP17
64KB	pins 2 & 3 closed	pins 2 & 3 closed	Open	Open
128KB	pins 1 & 2 closed	pins 1 & 2 closed	Closed	Open
256KB	pins 2 & 3 closed	pins 2 & 3 closed	Closed	Closed

CPU TYPE CONFIGURATION
Type	JP14	JP20	JP25	JP27
80386	Open	pins 2 & 3 closed	pins 1 & 2 closed	pins 1 & 2 closed
80486	Closed	pins 1 & 2 closed	pins 2 & 3 closed	pins 2 & 3 closed

CPU TYPE CONFIGURATION (80386DX/CX486DLC)
Type	JP14	JP15	JP20	JP25	JP27
80386DX (PQFP)	Open	Open	2 & 3	1 & 2	1 & 2
80386DX (PGA)	Open	Closed	2 & 3	1 & 2	1 & 2
CX486DLC (PGA)	Open	Closed	2 & 3	1 & 2	1 & 2
Note: Pins designated should be in the closed position.

CPU SPEED CONFIGURATION (80386DX/CX486DLC)
Speed	JP6	JP7	JP8	JP9	JP22
33MHz	Closed	Closed	Open	pins 2 & 3 closed	Open
40MHz	Closed	Closed	Closed	pins 2 & 3 closed	Open

CPU TYPE CONFIGURATION (80486)
Type	JP2	JP18	JP19
80486SX (PGA)	Open	Open	pins 2 & 3 closed
80487SX	pins 2 & 3 closed	Closed	pins 1 & 2 closed
ODP486SX	pins 2 & 3 closed	Closed	pins 1 & 2 closed
80486DX/DX2	pins 1 & 2 closed	Closed	pins 1 & 2 closed

CPU SPEED CONFIGURATION (80486)
Speed	JP6	JP7	JP8	JP9	JP22
25MHz	Open	Open	Open	pins 1 & 2 closed	Closed
33MHz	Open	Open	Closed	pins 1 & 2 closed	Open
40MHz	Open	Closed	Closed	pins 1 & 2 closed	Open
50iMHz	Open	Open	Open	pins 1 & 2 closed	Closed
50MHz	Open	Closed	Open	pins 1 & 2 closed	Open
66iMHz	Open	Open	Closed	pins 1 & 2 closed	Open

VESA IDE CONFIGURATION
IDE	JP1	JP12	JP13
IDE2	Open	Open	Closed
IDE3	Open	Closed	Open
IDE4	Closed	Open	Open