VL-BUS 486 MAIN BOARD Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX/80486DX2
Processor Speed	25/33/40/50(internal)/50/66(internal)MHz
Chip Set	UNI
Max. Onboard DRAM	32MB
Cache	64/128/256KB
BIOS	AMI/Award
Dimensions	330mm x 218mm
I/O Options	32-bit VESA local bus slots (2)

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	CN1	External battery	CN6
Speaker	CN3	Reset switch	CN8
Turbo LED	CN4	Power LED	LED1
Turbo switch	CN5	32-bit VESA local bus slots	S1 & S2

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	CMOS memory normal	JP12	pins 1 & 2 closed
	CMOS memory clear	JP12	pins 2 & 3 closed
»	FAST A20 enabled	JP17	pins 1 & 2 closed
	FAST A20 disabled	JP17	pins 2 & 3 closed
»	Monitor type select color	JP18	Closed
	Monitor type select monochrome	JP18	Open
»	Factory configured - do not alter	JP23	pins 1 & 2 closed
»	Factory configured - do not alter	JP24	pins 1 & 2 closed
»	Factory configured - do not alter	JP25	pins 1 & 2 closed
»	Factory configured - do not alter	JP26	pins 2 & 3 closed
»	Power good signal detect from power supply	JP27	pins 2 & 3 closed
	Power good signal detect from board	JP27	pins 1 & 2 closed
»	Factory configured - do not alter	JP28	pins 2 & 3 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
8MB	(4) 1M x 9	(4) 1M x 9
16MB	(4) 4M x 9	NONE
32MB	(4) 4M x 9	(4) 4M x 9

CACHE CONFIGURATION
Size	Bank 0	Bank 1	TAG write through U15	TAG write back U14,U15
64KB	(4) 8K x 8	(4) 8K x 8	8K x 8	(2) 8K x 8
128KB	(4) 32K x 8	NONE	8K x 8	(2) 8K x 8
256KB	(4) 32K x 8	(4) 32K x 8	32K x 8	(2) 32K x 8

CACHE JUMPER CONFIGURATION
Size	JP1	JP2	JP3	JP4	JP5	JP6	JP7
64KB write through	N/A	N/A	1 & 2	1 & 2	2 & 3	1 & 2	1 & 2
64KB write back	1 & 2	1 & 2	1 & 2	1 & 2	2 & 3	1 & 2	1 & 2
128KB write through	N/A	N/A	2 & 3	1 & 2	1 & 2	1 & 2	2 & 3
128KB write back	2 & 3	1 & 2	2 & 3	1 & 2	1 & 2	1 & 2	2 & 3
256KB write through	N/A	N/A	2 & 3	2 & 3	2 & 3	2 & 3	2 & 3
256KB write back	2 & 3	2 & 3	2 & 3	2 & 3	2 & 3	2 & 3	2 & 3
Note:Pins designated should be in the closed position.

CPU SPEED CONFIGURATION
Speed	JP20	JP21	JP22
25MHz	Closed	Open	Closed
33MHz	Open	Closed	Closed
40MHz	Closed	Open	Open
50iMHz	Closed	Open	Closed
50MHz	Open	Closed	Open
66iMHz	Open	Closed	Closed

CPU TYPE CONFIGURATION
CPU Type	JP13	JP14	JP15	JP16
80486SX PGA	open	pins 2 & 3 closed	Open	Closed
80486 SX PQFP	open	pins 2 & 3 closed	Open	Open
80487SX	pins 2 & 3 closed	pins 1 & 2 closed	Closed	N/A
80486DX, DX2	pins 1 & 2 closed	pins 1 & 2 closed	Closed	N/A

VESA WAIT STATE/BUS SPEED CONFIGURATION
CPU speed	Wait states	JP8	JP9	JP10	JP11
< 33MHz	0 wait states	pins 1 & 2	pins 1 & 2	pins 1 & 2	pins 1 & 2
> 33MHz	1 wait state	pins 2 & 3	pins 2 & 3	pins 2 & 3	pins 2 & 3
Note: Pins designated should be in the closed position.