DIMENSION 486SX/25, 486DX/33, 486DX2/50 Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX/80486DX2
Processor Speed	25/33/50(internal)/50/66(internal)
Chip Set	OPTI
Max. Onboard DRAM	64MB
SRAM Cache	64/256KB (optional module)
BIOS	AMI
Dimensions	330mm x 218mm
I/O Options	Floppy drive interface, IDE interface, bus mouse port parallel port, serial port (2), VGA port
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
PS/2 mouse	J1	IDE interface LED	J23
IDE interface	J5	Reset switch	J24
Floppy drive interface	J6	Speaker	J25
Parallel port	J8	Power LED & keylock	J26
Serial port (COM B)	J9	VGA port	J27
Serial port (COM A)	J10

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Monitor type select color	W1	pins 1 & 2 closed
	Monitor type select monochrome	W1	pins 2 & 3 closed
»	CMOS memory normal operation	W2	pins 1 & 2 closed
	CMOS memory clear	W2	pins 2 & 3 closed
»	I/O bus speed select SYSCLK/2	W3	pins 2 & 3 closed
	I/O bus speed select SYSCLK/1	W3	pins 1 & 2 closed
»	On-board VGA enabled	W10	pins 1 & 2 closed
	On-board VGA disabled	W10	pins 2 & 3 closed

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2	Bank 3
1MB	(1) 256K x 36	NONE	NONE	NONE
2MB	(1) 256K x 36	(1) 256K x 36	NONE	NONE
3MB	(1) 256K x 36	(1) 256K x 36	(1) 256K x 36	NONE
4MB	(1) 256K x 36	(1) 256K x 36	(1) 256K x 36	(1) 256K x 36
4MB	(1) 1M x 36	NONE	NONE	NONE
5MB	(1) 1M x 36	(1) 256K x 36	NONE	NONE
6MB	(1) 1M x 36	(1) 256K x 36	(1) 256K x 36	NONE
8MB	(1) 1M x 36	(1) 1M x 36	NONE	NONE
9MB	(1) 1M x 36	(1) 1M x 36	(1) 256K x 36	NONE
10MB	(1) 1M x 36	(1) 1M x 36	(1) 256K x 36	(1) 256K x 36
12MB	(1) 1M x 36	(1) 1M x 36	(1) 1M x 36	NONE
16MB	(1) 1M x 36	(1) 1M x 36	(1) 1M x 36	(1) 1M x 36
16MB	(1) 4M x 36	NONE	NONE	NONE
17MB	(1) 4M x 36	(1) 256K x 36	NONE	NONE
18MB	(1) 4M x 36	(1) 256K x 36	(1) 256K x 36	NONE
20MB	(1) 4M x 36	(1) 1M x 36	NONE	NONE
24MB	(1) 4M x 36	(1) 1M x 36	(1) 1M x 36	NONE
32MB	(1) 4M x 36	(1) 4M x 36	NONE	NONE
33MB	(1) 4M x 36	(1) 4M x 36	(1) 256K x 36	NONE
34MB	(1) 4M x 36	(1) 4M x 36	(1) 256K x 36	(1) 256K x 36
36MB	(1) 4M x 36	(1) 4M x 36	(1) 1M x 36	NONE
40MB	(1) 4M x 36	(1) 4M x 36	(1) 1M x 36	(1) 1M x 36
48MB	(1) 4M x 36	(1) 4M x 36	(1) 4M x 36	NONE
64MB	(1) 4M x 36	(1) 4M x 36	(1) 4M x 36	(1) 4M x 36

CPU TYPE CONFIGURATION
CPU	Jumper W6	Jumper W7	Jumper W8
80486DX2	pins 1 & 2 closed	pins 1 & 2 closed	pins 2 & 3 closed
80486DX	pins 1 & 2 closed	pins 1 & 2 closed	pins 2 & 3 closed
80487SX	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
80486SX	pins 2 & 3 closed	pins 2 & 3 closed	open

SRAM JUMPER CONFIGURATION
Size	Jumper W4	Jumper W5	Jumper W9
64KB	pins 2 & 3 closed	pins 2 & 3 closed	pins 2 & 3 closed
256KB	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed

VIDEO SWITCH CONFIGURATION (SW1)
Mode	switch 1	switch 2	switch 3	switch 4	switch 5
56Hz vertical refresh	open	open	N/A	N/A	N/A
60Hz vertical refresh	open	closed	N/A	N/A	N/A
72Hz vertical refresh	closed	open	N/A	N/A	N/A
Enable interlaced	N/A	N/A	open	open	N/A
60Hz non-interlaced	N/A	N/A	open	closed	N/A
72Hz non-interlaced	N/A	N/A	closed	open	N/A
31.5KHz horizontal scan rate	N/A	N/A	N/A	N/A	open
40KHz horizontal scan rate	N/A	N/A	N/A	N/A	closed

VRAM CONFIGURATION
Size	VRAM	SW1/switch 6
512KB	(2) 256K x 4	closed
1MB	(4) 256K x 4	open