OPTI-495SX Motherboard Settings and Configuration

Device Type	Mainboard
Processor	80386DX/80486SX/80487SX/80486DX/80486DX2/ODP486
Processor Speed	25/33/40/50(internal)/50/66(internal)MHz
Chip Set	OPTI495SX
Maximum Onboard Memory	32MB
Cache	64/128/256KB
BIOS	AMI
Dimensions	254mm x 218mm
I/O Options	32-bit VESA local bus slot
NPU Options	80387DX

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	J1	Reset switch	J5
Speaker	J2	External battery	JP18
Turbo switch	J3	32-bit VESA local bus slot	SL1
Turbo LED	J4

USER CONFIGURABLE SETTINGS
Function		Label	Position
»	Factory configured - do not alter	JP8	Unidentified
»	Factory configured - do not alter	JP9	Unidentified
»	Factory configured - do not alter	JP10	Unidentified
»	Factory configured - do not alter	JP11	Unidentified
	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
	Battery type select external	JP18	Closed
»	Factory configured - do not alter	JP23	Unidentified
»	Factory configured - do not alter	JP29	Unidentified

SIMM 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
5MB	(4) 1M x 9	(4) 256K 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
17MB	(4) 4M x 9	(4) 256K 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

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

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

CPU SPEED SELECTION
Speed	JP14	JP15	JP16	JP22
25MHz	Pins 1 & 2 closed	Open	Closed	N/A
33MHz (386)	Pins 2 & 3 closed	Closed	Open	Closed
33MHz	Pins 1 & 2 closed	Closed	Open	N/A
40MHz (386)	Pins 2 & 3 closed	Open	Open	Open
50iMHz	Pins 1 & 2 closed	Open	Closed	N/A
50MHz	Pins 2 & 3 closed	Open	Closed	N/A
66iMHz	Pins 1 & 2 closed	Closed	Open	N/A

CPU TYPE SELECTION
Type	JP1	JP2	JP4
80486SX	Open	Pins 2 & 3 closed	Open
80487SX	Closed	Pins 1 & 2 closed	Pins 2 & 3 closed
80486DX	Closed	Pins 1 & 2 closed	Pins 1 & 2 closed
80486DX2	Closed	Pins 1 & 2 closed	Pins 1 & 2 closed
ODP486	Closed	Pins 1 & 2 closed	Pins 2 & 3 closed

CPU TYPE SELECTION
Type	JP3	JP5	JP21	JP24
80386 (PQFP)	Pins 2 & 3 closed	Pins 1 & 2 closed	Open	Pins 1 & 2 closed
80486 (PGA)	Pins 1 & 2 closed	Pins 2 & 3 closed	Closed	Pins 2 & 3 closed
80486 (PQFPGA)	Pins 1 & 2 closed	Pins 2 & 3 closed	Open	Pins 2 & 3 closed