486 VL450C-1 Motherboard Settings and Configuration

Processor	80486SX/80486DX/80486DX2
Processor Speed	20/25/33/40(internal)/50(internal)/50/66(internal)MHz
Chip Set	SIS
Max. Onboard DRAM	32MB
Cache	64/128/256KB
BIOS	AMI
Dimensions	230mm x 218mm
I/O Options	32-bit VESA local bus slots (2)
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
External battery	J1	Turbo LED	J5
Power LED & keylock	J2	Reset switch	J6
Speaker	J3	32-bit VESA Local bus slots	SL1 & SL2
Turbo switch	J4

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Factory configured - do not alter	J7	Open
»	A20 type select fast gate	JP2	pins 1 & 2 closed
	A20 type select keyboard controller gate	JP2	pins 2 & 3 closed
»	CMOS memory normal operation	JP3	Open
	CMOS memory clear	JP3	pins 2 & 3 closed
»	VESA local bus normal operation	JP27	pins 1 & 2 closed
	VESA local bus compatibility problems (See note below)	JP27	pins 2 & 3 closed
»	PQFP CPU enabled	JSX6	Open
	PQFP CPU disabled	JSX6	Closed
Note: If compatibility problems arise with nonstandard VESA local bus peripherals, jumper pins 2 & 3.

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
20MB	(4) 1M x 9	(4) 4M 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 or (1) 32K x 8
128KB	(4) 32K x 8	NONE	(1) 8K x 8 or (1) 32K x 8
256KB	(4) 32K x 8	(4) 32K x 8	(1) 32K x 8

CACHE JUMPER CONFIGURATION
Size	JP4	JP5	JP6	JP7
64KB	Open	Open	Open	Open
128KB	Closed	pins 1 & 2 closed	Open	Closed
256KB	Closed	pins 2 & 3 closed	Closed	Closed

CPU TYPE CONFIGURATION
Type	JSX1	JSX2	JSX3	JSX4	JSX5
80486SX	Open	Open	Open	Closed	Open
80487SX	Open	Closed	Closed	Open	Closed
80486DX/DX2	Closed	Open	Closed	Open	Closed
Overdrive	Open	Closed	Closed	Open	Closed

CPU SPEED CONFIGURATION
Speed	JP20	JP21	JP22
20MHz	Open	Open	Open
25MHz	Closed	Open	Open
33MHz	Closed	Closed	Closed
40MHz	Closed	Closed	Open
50iMHz	Closed	Open	Open
50MHz	Open	Open	Closed
66iMHz	Closed	Closed	Closed

VESA WAIT STATE/BUS SPEED CONFIGURATION
CPU speed	Wait states	JP8	JP9	JP10	JP11
< 33MHz	0 wait states	Open	Open	Open	Open
> 33MHz	1 wait state	Short	Short	Short	Short