OPTI-495SX 3/486WB CACHE Motherboard Settings and Configuration

Processor	80386DX/80486SX/80487SX/80486DX/ODP486SX/80486DX2
Processor Speed	25/33/40/50(internal)/50/66(internal)MHz
Chip Set	OPTI
Max. Onboard DRAM	32MB
Cache	64/128/256KB
BIOS	AMI
Dimensions	254mm x 218mm
I/O Options	32-bit VESA local bus slot (Non-functional)
NPU Options	80387

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	J1	Reset switch	J5
Speaker	J2	External battery	JP18
Turbo switch	J3	32-bit VESA card	S1
Turbo LED	J4

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Factory configured - do not alter	JP8	unknown
»	Factory configured - do not alter	JP9	unknown
»	Factory configured - do not alter	JP10	unknown
»	Factory configured - do not alter	JP11	unknown
»	Monitor type select color	JP17	closed
	Monitor type select monochrome	JP17	open
»	CMOS memory normal operation	JP18	pins 2 & 3 closed
	CMOS memory clear	JP18	pins 3 & 4 closed
	External battery select	JP18	connected
»	Factory configured - do not alter	JP23	open

CACHE JUMPER CONFIGURATION
Size	JP6	JP7	JP12	JP13
64KB	open	open	open	pins 2 & 3 closed
128KB	open	closed	closed	pins 1 & 2 closed
256KB	closed	closed	closed	pins 2 & 3 closed

CACHE CONFIGURATION
Size	Cache	Location	TAG
64KB	(8) 8K x 8	Banks 0 & 1	(1) 8K x 8
128KB	(4) 32K x 8	Bank 0	(1) 8K x 8
256KB	(8) 32K x 8	Banks 0 & 1	(1) 32K x 8

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) 1 x 9
8MB	(4) 1M x 9	(4) 1M x 9
16MB	(4) 4M x 9	NONE
20MB	(4) 1M x 9	(4) 4M x 9
32MB	(4) 4M x 9	(4) 4M x 9

CPU MODE CONFIGURATION
Mode	JP3	JP5	JP20	JP21	JP24
486 (PQFP)	pins 1 & 2	pins 2 & 3	open	N/A	pins 2 & 3
486 (PGA)	pins 1 & 2	pins 2 & 3	closed	closed	pins 2 & 3
386 (PQFP)	pins 2 & 3	pins 1 & 2	N/A	open	pins 1 & 2

CPU TYPE CONFIGURATION (PQFP)
Type	JP14	JP22	JP51	JP52
80486SX-33MHz	pins 1 & 2 closed	N/A	open	closed
80486SX-25MHz	pins 1 & 2 closed	N/A	closed	open
80386DX-40MHz	pins 2 & 3 closed	open	open	open
80386DX-33MHz	pins 2 & 3 closed	closed	open	closed

CPU TYPE CONFIGURATION (PGA)
Type	JP1	JP2	JP4	JP14	JP51	JP52
80486DX2-66MHz	closed	pins 1 & 2	pins 1 & 2	pins 1 & 2	open	closed
80486DX2-50MHz	closed	pins 1 & 2	pins 1 & 2	pins 1 & 2	closed	open
ODP486SX-33MHz	closed	pins 1 & 2	pins 2 & 3	pins 1 & 2	open	closed
ODP486SX-25MHz	closed	pins 1 & 2	pins 2 & 3	pins 1 & 2	closed	open
80486DX-50MHz	closed	pins 1 & 2	pins 1 & 2	pins 2 & 3	closed	open
80486DX-33MHz	closed	pins 1 & 2	pins 1 & 2	pins 1 & 2	open	closed
80486DX-25MHz	closed	pins 1 & 2	pins 1 & 2	pins 1 & 2	closed	open
80487SX-33MHz	closed	pins 1 & 2	pins 2 & 3	pins 1 & 2	open	closed
80487SX-25MHz	closed	pins 1 & 2	pins 2 & 3	pins 1 & 2	closed	open
80486SX-33MHz	open	pins 2 & 3	open	pins 1 & 2	open	closed
80486SX-25MHz	open	pins 2 & 3	open	pins 1 & 2	closed	open