486U (REV. 1.1C) Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX
Processor Speed	20/25/33/40/50MHz
Chip Set	UMC
Video Chip Set	None
Maximum Onboard Memory	64MB (32MB on external memory card)
Maximum Video Memory	None
Cache	64/128/256KB
BIOS	AMI
Dimensions	330mm x 220mm
I/O Options	External memory card
NPU Options	4167

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	J1	External battery	J7
Speaker	J2	Turbo LED	W1 pins 2 & 3
Turbo switch	J4	Reset switch	W14

USER CONFIGURABLE SETTINGS
Function		Label	Position
	Turbo mode enabled	J4	Pins 1 & 2 closed
	Turbo mode disabled	J4	Open
»	Factory configured - do not alter	J5	Pins 1 & 2 closed
»	Factory configured - do not alter	W2	Open
»	Factory configured - do not alter	W5	Pins 1 & 2 closed
»	Factory configured - do not alter	W11	Open

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2	Bank 3
1MB	(4) 256K x 9	None	None	None
2MB	(4) 256K x 9	(4) 256K x 9	None	None
3MB	(4) 256K x 9	(4) 256K x 9	(4) 256K x 9	None
4MB	(4) 256K x 9	(4) 256K x 9	(4) 256K x 9	(4) 256K x 9
4MB	(4) 1M x 9	None	None	None
5MB	(4) 256K x 9	(4) 1M x 9	None	None
6MB	(4) 256K x 9	(4) 256K x 9	(4) 1M x 9	None
8MB	(4) 1M x 9	(4) 1M x 9	None	None
9MB	(4) 256K x 9	(4) 1M x 9	(4) 1M x 9	None
10MB	(4) 256K x 9	(4) 256K x 9	(4) 1M x 9	(4) 1M x 9
12MB	(4) 1M x 9	(4) 1M x 9	(4) 1M x 9	None
16MB	(4) 1M x 9	(4) 1M x 9	(4) 1M x 9	(4) 1M x 9
16MB	(4) 4M x 9	None	None	None
20MB	(4) 1M x 9	(4) 4M x 9	None	None
24MB	(4) 1M x 9	(4) 1M x 9	(4) 4M x 9	None
32MB	(4) 4M x 9	(4) 4M x 9	None	None
36MB	(4) 1M x 9	(4) 4M x 9	(4) 4M x 9	None
40MB	(4) 1M x 9	(4) 1M x 9	(4) 4M x 9	(4) 4M x 9
48MB	(4) 4M x 9	(4) 4M x 9	(4) 4M x 9	None
64MB	(4) 4M x 9	(4) 4M x 9	(4) 4M x 9	(4) 4M x 9
Note: Banks 2 & 3 are located on the external memory card.

CACHE CONFIGURATION
Size	Bank 0	Bank 1
64KB	(4) 8K x 8	(4) 8K x 8
128KB	(4) 32K x 8	None
256KB	(4) 32K x 8	(4) 32K x 8

CACHE JUMPER CONFIGURATION
Size	W6	W8	W9	W12	W13
None	Open	Open	Open	Open	Open
64KB	1 & 2	1 & 2	2 & 3	1 & 2	1 & 2
128KB	1 & 2	2 & 3	2 & 3	2 & 3	1 & 2
256KB	2 & 3	2 & 3	2 & 3	1 & 2	2 & 3
Note: Pins designated should be in the closed position.

CACHE TAG CONFIGURATION
Size	U2	U3	U4	U5
64KB	(1) 16K x 4	(1) 16K x 4	(1) 16K x 4	(1) 16K x 4
128KB	(1) 16K x 4	(1) 16K x 4	(1) 16K x 4	(1) 16K x 4
256KB	(1) 16K x 4	(1) 16K x 4	(1) 16K x 4	(1) 16K x 4
Note: U4 & U5 must be installed even if no cache is installed.

CACHE TAG JUMPER CONFIGURATION
Size	W7
No cache installed	Closed
Chip installed at U3	Open
Chip not installed at U3	Closed

CPU TYPE SELECTION
Type	J3	W3	W4	W10	W15
80486SX	Open	2 & 3	Open	Open	Open
80487SX	2 & 3	1 & 2	Closed	Closed	Open
80486DX	1 & 2	1 & 2	Closed	Open	Open
Note: Pins designated should be in the closed position.