T486SX-20/T486DX-25/T486DX-33 Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX
Processor Speed	20/25/33MHz
Chip Set	ACT
Max. Onboard DRAM	32MB
Cache	None
BIOS	AMI
Dimensions	330mm x 218mm
I/O Options	None
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & Keylock	JP22	Speaker	JP28
Reset switch	JP24	Turbo switch	JP30
External battery	JP25	Turbo LED	JP31

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	RAM speed select fast (40 to 70ns)	JP4 & JP5	pins 1 & 2 closed
	RAM speed select slow (80 to 120ns)	JP4 & JP5	pins 2 & 3 closed
»	Video BIOS cacheable	JP7	pins 1 & 2 closed
	Video BIOS non-cacheable	JP7	pins 2 & 3 closed
»	Factory configured - do not alter	JP11	N/A
»	Monitor type select color	JP23	pins 2 & 3 closed
	Monitor type select monochrome	JP23	pins 1 & 2 closed
»	Battery select internal	JP26	pins 1 & 2 closed
	Battery select external	JP26	pins 2 & 3 closed
»	Power good signal detect from power supply	JP27	pins 1 & 2 closed
	Power good signal detect from board	JP27	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

DRAM JUMPER CONFIGURATION
Size	JP8	JP9	JP10
1MB	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
2MB	pins 1 & 2 closed	pins 1 & 2 closed	pins 2 & 3 closed
4MB	pins 1 & 2 closed	pins 2 & 3 closed	pins 1 & 2 closed
8MB	pins 1 & 2 closed	pins 2 & 3 closed	pins 2 & 3 closed
16MB	pins 2 & 3 closed	pins 2 & 3 closed	pins 1 & 2 closed
32MB	pins 2 & 3 closed	pins 2 & 3 closed	pins 2 & 3 closed

CPU TYPE CONFIGURATION
Type	JP2	JP3	JP6	JP12
80486SX - 20MHz	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
80486SX - 33MHz	pins 2 & 3 closed	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
80487SX - 20MHz	pins 1 & 2 closed	pins 1 & 2 closed	pins 2 & 3 closed	pins 2 & 3 closed
80486DX - 25/33 MHz	pins 2 & 3 closed	pins 2 & 3 closed	pins 2 & 3 closed	pins 2 & 3 closed