P486DX Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX/80486DX2
Processor Speed	20/25/33/50(internal)/50/66(internal)MHz
Chip Set	OPTI
Max. Onboard DRAM	32MB
SRAM Cache	64/128/256KB
BIOS	AMI
Dimensions	220mm x 220mm
I/O Options	None
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
External battery	J9	Turbo switch	JP13
Power LED & keylock	J20	Turbo LED	JP14
Speaker	JP12	Reset switch	S1

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Monitor type select monochrome	JP1	open
	Monitor type select color	JP1	closed
»	Battery select internal	JP2	pins 2 & 3 closed
	Battery select external	JP2	open
	CMOS memory clear	JP2	pins 1 & 2 closed
»	CPU speed select iOSC/2 (oscillator located at U30)	JP7 JP11	pins 2 & 3 closed open
	CPU speed select iOSC/1 (oscillator located at U30)	JP7 JP11	pins 1 & 2 closed closed

CPU TYPE CONFIGURATION
CPU Type	JP5	JP6	JP10
80486DX/80486DX2	pins 1 & 2 closed	closed	pins 1 & 2 closed
80487SX	pins 1 & 2 closed	closed	pins 2 & 3 closed
80486SX	pins 2 & 3 closed	open	open

DRAM CONFIGURATION
Size	Bank 0	Bank 1
1MB	(4) 256K x 9	NONE
4MB	(4) 1M x 9	NONE
5MB	(4) 256K x 9	(4) 1M x 9
8MB	(4) 1M x 9	(4) 1M x 9
16MB	(4) 4M x 9	NONE
20MB	(4) 4M x 9	(4) 1M x 9
32MB	(4) 4M x 9	(4) 4M x 9

SRAM JUMPER CONFIGURATION
Jumper	64KB	128KB	256KB
JP3	pins 2 & 3 closed	pins 1 & 2 closed	pins 2 & 3 closed
JP4	pins 2 & 3 closed	pins 1 & 2 closed	pins 2 & 3 closed
JP8	open	open	closed
JP9	open	closed	closed
JP15	open	closed	closed
JP16	open	open	closed

SRAM CONFIGURATION
Size	Cache SRAM	Location	TAG
64KB	(8) 8K x 8	Banks 0 & 1	(1) 8K x 8
128KB	(4) 32K x 8	Bank 0	(1) 8K x 8
256KB	(8) 32K x 8	Banks 0 & 1	(1) 8K x 8