SIH 486B Motherboard Settings and Configuration

Processor	80486SX/80486DX/P23N/P23T
Processor Speed	16/20/25/33/40/50MHz
Chip Set	ASIC
Video Chip Set	None
Maximum Onboard Memory	32MB
Maximum Video Memory	None
Cache	32/64/128/256KB
BIOS	AMI
Dimensions	218mm x 218mm
I/O Options	None
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
External battery	J1	Turbo LED	J5
Power LED & keylock	J3	Turbo switch	J7
Speaker	J4	Reset switch	J8

USER CONFIGURABLE SETTINGS
Function		Label	Position
	Monitor type select color	J2	Open
	Monitor type select monochrome	J2	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
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 0	TAG 1
32KB	(4) 8K x 8	None	(1) 16K x 4	(1) 8K x 8
64KB	(4) 8K x 8	(4) 8K x 8	(1) 16K x 4	(1) 8K x 8
128KB	(4) 32K x 8	None	(1) 16K x 4	(1) 32K x 8
256KB	(4) 32K x 8	(4) 32K x 8	(1) 16K x 4	(1) 32K x 8

CACHE JUMPER CONFIGURATION
Size	J11	J12	J13	J14	J15
32KB	1 & 2	Open	1 & 2	1 & 2	1 & 2
64KB	2 & 3	Open	1 & 2	2 & 3	1 & 2
128KB	1 & 2	1 & 2	2 & 3	2 & 3	2 & 3
256KB	2 & 3	2 & 3	2 & 3	2 & 3	2 & 3
Note: Pins designated should be in the closed position.

CACHE JUMPER CONFIGURATION (CON’T)
Size	J16	J17	J18	J19
32KB	Pins 1 & 2 closed	Pins 1 & 2 closed	Pins 1 & 2 closed	Pins 1 & 2 closed
64KB	Pins 1 & 2 closed	Pins 2 & 3 closed	Pins 1 & 2 closed	Pins 1 & 2 closed
128KB	Pins 1 & 2 closed	Pins 2 & 3 closed	Pins 2 & 3 closed	Pins 1 & 2 closed
256KB	Pins 2 & 3 closed	Pins 2 & 3 closed	Pins 2 & 3 closed	Pins 2 & 3 closed

CPU SPEED SELECTION
Speed	OSC installed in Y1	J9
16MHz	32MHz	Pins 2 & 3 closed
20MHz	40MHz	Pins 2 & 3 closed
25MHz	50MHz	Pins 2 & 3 closed
25MHz	25MHz	Pins 1 & 2 closed
33MHz	33MHz	Pins 1 & 2 closed
50MHz	50MHz	Pins 1 & 2 closed

CPU TYPE SELECTION
Type	J20	J21	J22
80486SX	Open	Pins 2 & 3 closed	Open
80486DX	Closed	Pins 1 & 2 closed	Pins 1 & 2 closed
P23N	Closed	Pins 1 & 2 closed	Pins 2 & 3 closed
P23T	Closed	Pins 1 & 2 closed	Pins 1 & 2 closed