SIS 486 Motherboard Settings and Configuration

Processor	CX486SX/80486SX/80487SX/CX486DX/80486DX/80486DX2
Processor Speed	25/33/40/50(internal)/50/66(internal)MHz
Chip Set	SIS
Max. Onboard DRAM	64MB
Cache	128/256KB
BIOS	AMI
Dimensions	254mm x 220mm
I/O Options	32-bit VESA local bus slots (3)
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
Auxiliary keyboard connector	CN1	Turbo switch	JP22 pins 15 - 17
External battery	CN3	Reset switch	JP22 pins 19 - 20
Power LED & keylock	JP22 pins 1 - 5	Bus mouse port	JP22 pins 19 - 20
Speaker	JP22 pins 6 - 10	32-bit VESA local bus slots	SL1 - SL3
Turbo LED	JP22 pins 12 - 13

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Battery type select internal	CN3	pins 2 & 3 closed
	Battery type select external	CN3	Closed
»	Factory configured - do not alter	JGPC	N/A
»	Monitor type select monochrome	JP1	Open
	Monitor type select color	JP1	Closed
»	PQFP CPU disabled	JP5	Closed
	PQFP CPU enabled	JP5	Open
»	CPU speed select 50MHz (Cyrix only)	JP6	pins 1 & 2 closed
	CPU speed select <50MHz (Cyrix only)	JP6	pins 2 & 3 closed
»	CPU type select all	JP16	pins 2 & 3 closed
	CPU type select 80486DX-40/50 only	JP16	pins 1 & 2 closed
»	VESA card select normal	JP23	Open
	VESA card select Genoa	JP23	Closed

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2
4MB	(4) 256K x 9	(1) 256K x 36	(1) 512K x 36
4MB	NONE	(1) 512K x 36	(1) 512K x 36
8MB	(4) 1M x 9	(1) 512K x 36	(1) 512K x 36
20MB	(4) 4M x 9	(1) 512K x 36	(1) 512K x 36
4MB	(4) 1M x 9	NONE	NONE
8MB	NONE	(1) 1M x 36	(1) 1M x 36
8MB	(4) 1M x 9	(1) 1M x 36	NONE
12MB	(4) 1M x 9	(1) 1M x 36	(1) 1M x 36
16MB	NONE	(1) 4M x 36	NONE
16MB	(4) 4M x 9	NONE	NONE
32MB	NONE	(1) 4M x 36	(1) 4M x 36
64MB	(4) 4M x 9	(1) 4M x 36	(1) 4M x 36

DRAM CONFIGURATION
Size	JPA	JPB	JPC
4MB	pins 1 & 2 closed	pins 4 & 5 closed	pins 1 & 2 closed
4MB	pins 2 & 3 closed	Open	Open
8MB	pins 2 & 3 closed	pins 2 & 3 closed	pins 1 & 2 closed
20MB	pins 2 & 3 closed	pins 2 & 3 closed	pins 1 & 2 closed
4MB	Open	Open	pins 2 & 3 closed
8MB	pins 2 & 3 closed	Open	Open
8MB	Open	pins 4 & 5 closed	pins 1 & 2 closed
12MB	pins 1 & 2 closed	pins 4 & 5 closed	pins 1 & 2 closed
16MB	Open	Open	Open
16MB	Open	Open	pins 2 & 3 closed
32MB	pins 2 & 3 closed	Open	Open
64MB	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed

CACHE CONFIGURATION
Size	Bank 0	Bank 1	TAG
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	JP2	JP3	JP4
128KB	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
256KB	pins 2 & 3 closed	pins 2 & 3 closed	pins 2 & 3 closed

CPU TYPE CONFIGURATION
Type	JP12	JP13	JP15
80486SX	Open	pins 2 & 3 closed	Open
80487SX	pins 2 & 3 closed	pins 1 & 2 closed	Closed
80486DX	pins 1 & 2 closed	pins 1 & 2 closed	Closed
80486DX2	pins 1 & 2 closed	pins 1 & 2 closed	Closed

CPU SPEED CONFIGURATION
Speed	JS0	JS1	JS2
25MHz	Open	Open	Closed
33MHz	Closed	Open	Open
40MHz	Closed	Closed	Open
50iMHz	Open	Open	Closed
50MHz	Open	Closed	pins 1 & 2 closed
66iMHz	Closed	Open	Open

VESA WAIT STATE CONFIGURATION
Wait states	JP8
0 wait states	pins 1 & 2 closed
1 wait state	pins 2 & 3 closed

BUS SPEED CONFIGURATION
CPU speed	JP9
<= 33MHz	pins 1 & 2 closed
> 33MHz	pins 2 & 3 closed