A486DX4/SIS III Motherboard Settings and Configuration

Processor	AM486SX/80486SX/CX486DX/AM486DX/80486DX/AM486DX2/ 80486DX2/AM486DX4/80486DX4
Processor Speed	20/25/33/40/50(internal)/50/66(internal)/75(internal)/ 100(internal)MHz
Chip Set	SIS
Video Chip Set	None
Maximum Onboard Memory	64MB
Maximum Video Memory	None
Cache	32/64/128/256/512KB
BIOS	AMI
Dimensions	254mm x 218mm
I/O Options	32-bit VESA local bus slots (3)
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	J1	Power LED	LED1
Speaker	J2	Turbo switch	S1
Turbo LED	J4	32-bit VESA local bus slots	SL1 - SL3
Reset switch	J5

USER CONFIGURABLE SETTINGS
Function		Label	Position
»	Factory configured - do not alter	J7	Unidentified
»	Factory configured - do not alter	J9	Closed
»	Factory configured - do not alter	J11	Open
»	Factory configured - do not alter	J12	Open
»	Factory configured - do not alter	JP17	Pins 1 & 2 closed
	RC pin used for break switch	JP20	Pins 1 & 2 closed
	RC pin used for RC	JP20	Pins 2 & 3 closed
	CPU type select any CPU type	JP27	Open
	CPU type select CX486S2 only	JP27	Closed
	Monitor type select CGA	JP38	Closed
	Monitor type select monochrome/EGA/VGA	JP38	Open
»	CMOS memory normal operation	JP39	Pins 1 & 2 closed
	CMOS memory clear	JP39	Pins 2 & 3 closed
»	Factory configured - do not alter	JP43	Pins 2 & 3 closed
»	Factory configured - do not alter	JP71	Open
	Flash BIOS not installed	JP73	Pins 1 & 2 closed
	Flash BIOS installed	JP73	Pins 2 & 3 closed
»	Factory configured - do not alter	JP74	Unidentified
»	Factory configured - do not alter	JP75	Unidentified
»	Factory configured - do not alter	JP78	Pins 1 & 2 closed
»	Factory configured - do not alter	JP79	Pins 2 & 3 closed
	Turbo disabled	TBSW	Pins 1 & 2 closed
	Turbo enabled	TBSW	Pins 2 & 3 closed
	Turbo enabled through S1	TBSW	Pins 4 & 5 closed

DRAM CONFIGURATION 1
Size	Bank 0
1MB	(4) 256K x 9
4MB	(4) 1M x 9
16MB	(4) 4M x 9
64MB	(4) 16M x 9

DRAM CONFIGURATION 2
Size	Bank 1	Bank 2
1MB	(1) 256K x 36	None
2MB	(1) 512K x 36	None
4MB	(1) 1M x 36	None
4MB	(1) 512K x 36	(1) 512K x 36
8MB	(1) 2M x 36	None
8MB	(1) 1M x 36	(1) 1M x 36
16MB	(1) 4M x 36	None

DRAM CONFIGURATION 2 (CON’T)
Size	Bank 1	Bank 2
16MB	(1) 2M x 36	(1) 2M x 36
32MB	(1) 8M x 36	None
32MB	(1) 4M x 36	(1) 4M x 36
64MB	(1) 8M x 36	(1) 8M x 36

DRAM JUMPER CONFIGURATION
Configuration	JP45	JP46
1	Pins 2 & 3 closed	Closed
2	Pins 1 & 2 closed	Open

CACHE CONFIGURATION
Size	Bank 0	Bank 1	TAG
32KB	(4) 8K x 8	None	(1) 8K x 8
64KB	(4) 8K x 8	(4) 8K x 8	(1) 8K x 8
128KB	(4) 32K x 8	None	(1) 8K x 8
256KB (A)	(4) 32K x 8	(4) 32K x 8	(1) 32K x 8
256KB (B)	(4) 64K x 8	None	(1) 32K x 8
512KB	(4) 128K x 8	None	(1) 32K x 8

CACHE JUMPER CONFIGURATION
Size	JP30	JP31	JP32	JP34	JP35	JP36	JP81
32KB	1 & 2	1 & 2	1 & 2	Open	1 & 2	1 & 2	2 & 3
64KB	2 & 3	1 & 2	1 & 2	1 & 2	2 & 3	1 & 2	2 & 3
128KB	2 & 3	2 & 3	1 & 2	2 & 3, 4 & 5	1 & 2	2 & 3	2 & 3
256KB (A)	2 & 3	2 & 3	2 & 3	1 & 2, 3 & 4	2 & 3	2 & 3	2 & 3
256KB (B)	2 & 3	2 & 3	2 & 3	2 & 3, 4 & 5	1 & 2	2 & 3	2 & 3
512KB	2 & 3	2 & 3	2 & 3	2 & 3, 4 & 5	1 & 2	2 & 3	1 & 2
Note: Pins designated should be in the closed position.

CPU SPEED SELECTION
Speed	JP5	JP6	JP7
20MHz	Closed	Open	Closed
25MHz	Closed	Closed	Open
33MHz	Open	Closed	Closed
40MHz	Closed	Open	Open
50iMHz	Closed	Closed	Open
50MHz	Open	Open	Closed
66iMHz	Open	Closed	Closed
75iMHz	Closed	Closed	Open
100iMHz	Open	Closed	Closed

CPU TYPE SELECTION
Type	J13	JP8	JP10	JP12	JP13
AM486SX	Closed	2 & 3	2 & 3	Open	Open
80486SX	Closed	2 & 3	2 & 3	Open	Open
CX486DX	Open	2 & 3	2 & 3	2 & 3	2 & 3
AM486DX	Closed	2 & 3	2 & 3	Open	Open
80486DX	Closed	2 & 3	2 & 3	Open	Open
AM486DX2	Closed	2 & 3	2 & 3	Open	Open
80486DX2	Closed	2 & 3	2 & 3	Open	Open
AM486DX4	Closed	2 & 3	Open	Open	Open
80486DX4	Closed	2 & 3	Open	Open	Open
Note: Pins designated should be in the closed position.

CPU TYPE SELECTION (CON’T)
Type	JP18	JP19	JP24	JP25	JP28
AM486SX	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
80486SX	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
CX486DX	2 & 3	1 & 2	2 & 3	1 & 2, 3 & 4	Open
AM486DX	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
80486DX	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
AM486DX2	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
80486DX2	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
AM486DX4	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
80486DX4	1 & 2	2 & 3	4 & 5	2 & 3	1 & 2
Note: Pins designated should be in the closed position.

CPU TYPE SELECTION (CON’T)
Type	JP29	JP33	JP37	JP40
AM486SX	3 & 4	2 & 3	Open	1 & 2 or 2 & 3
80486SX	3 & 4	2 & 3	Open	1 & 2 or 2 & 3
CX486DX	2 & 3	1 & 2	3 & 4	1 & 2
AM486DX	3 & 4	1 & 2, 3 & 4	3 & 4	1 & 2 or 2 & 3
80486DX	3 & 4	1 & 2, 3 & 4	3 & 4	1 & 2 or 2 & 3
AM486DX2	3 & 4	1 & 2, 3 & 4	3 & 4	1 & 2 or 2 & 3
80486DX2	3 & 4	1 & 2, 3 & 4	3 & 4	1 & 2 or 2 & 3
AM486DX4	3 & 4	1 & 2, 3 & 4	3 & 4	1 & 2 or 2 & 3
80486DX4	3 & 4	1 & 2, 3 & 4	3 & 4	1 & 2 or 2 & 3
Note: Pins designated should be in the closed position.

CPU MULTIPLIER SELECTION
Multiplier	JP44
2x	Pins 1 & 2 closed
2.5x	Pins 2 & 3 closed
3x	Open

CPU VOLTAGE SELECTION
Voltage	Setting	JP80
3.45v	UMB on board	Auto detect
5v	UMB on board	Auto detect
3.45v	UMB not on board	No support
5v	UMB not on board	Closed

VL BUS WAIT STATE SELECTION
Setting	JP4
0	Pins 1 & 2 closed
1	Pins 2 & 3 closed

VL BUS SPEED SELECTION
Speed	JP3
<= 33MHz	Pins 1 & 2 closed
>33 MHz	Pins 2 & 3 closed