ISA 486S Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX
Processor Speed	20/25/33MHz
Chip Set	Symphony Haydn
Max. Onboard DRAM	32MB
Cache	64/128/256KB
BIOS	AMI
Dimensions	330mm x 218mm
I/O Options	32-bit external memory card
NPU Options	4167

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	CON1	Turbo switch	CON4
Speaker	CON2	Reset switch	CON5
Turbo LED	CON3	32-bit external memory card	S1

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Power good signal detect from power supply	JP1	pins 2 & 3 closed
	Power good signal detect from board	JP1	pins 1 & 2 closed
»	Monitor type select monochrome or other than CGA	JP5	pins 2 & 3 closed
	Monitor type select CGA	JP5	pins 1 & 2 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
5MB	(4) 1M x 9	(4) 256K x 9
8MB	(4) 1M x 9	(4) 1M x 9
16MB	(4) 4M x 9	NONE
17MB	(4) 4M x 9	(4) 256K x 9
20MB	(4) 4M x 9	(4) 1M x 9
32MB	(4) 4M x 9	(4) 4M x 9
Note:Onboard memory and external memory are independent and may be used in any combination.

EXTERNAL MEMORY CARD 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 (U27)	TAG (U28)
64KB	(4) 8K x 8	(4) 8K x 8	(1) 8K x 8	NONE
128KB	(4) 32K x 8	NONE	(1) 8K x 8	NONE
256KB	(4) 32K x 8	(4) 32K x 8	(1) 8K x 8	(1) 8K x 8
256KB	(4) 32K x 8	(4) 32K x 8	(1) 32K x 8	NONE

CACHE JUMPER CONFIGURATION
Size	TP7	RB1 & RB2
64KB	pins 2 & 3 closed	Position 1
128KB	pins 1 & 2 closed	Position 2
256KB	pins 2 & 3 closed	Position 3
Note:Location of TP7 is unverified.

CPU SWITCH CONFIGURATION
Type	SW1/1	SW1/2	SW1/3	SW1/4	SW1/5	SW1/6
80486SX	Off	Off	Off	Off	On	On
80487SX	On	On	On	Off	Off	Off
80486DX	On	On	On	Off	Off	Off