A4879 Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX
Processor Speed	25/50MHz
Chip Set	UMC
Max. Onboard DRAM	64MB
SRAM Cache	64/128/256KB
BIOS	AMI
Dimensions	220mm x 330mm
I/O Options	None
NPU Options	4167

CONNECTIONS
Purpose	Location	Purpose	Location
Power LED & keylock	J1	Reset switch	J4
Speaker	J2	Turbo LED	J5
Turbo switch	J3	External battery	J6

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Monitor type select color	W18	closed
	Monitor type select monochrome	W18	open
»	Battery type select internal	W22	closed
	Battery type select external	W22	open

SRAM JUMPER CONFIGURATION
Jumper	64KB	128KB	256KB
W2	pins 1 & 2 closed	pins 2 & 3 closed	pins 2 & 3 closed
W3	pins 1 & 2 closed	pins 1 & 2 closed	pins 2 & 3 closed
W4	open	pins 2 & 3 closed	pins 2 & 3 closed
W5	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
W6	open	closed	closed
W7	open	open	closed
W8	open	open	closed
W9	open	closed	closed

SRAM CONFIGURATION
Size	Cache SRAM	Location	TAG (U10)	TAG (U11)
64KB	(8) 8K x 8	Banks 0 & 1	(1) 16K x 4	(1) 8K x 8
128KB	(4) 32K x 8	Bank 0	(1) 16K x 4	(1) 32K x 8
256KB	(8) 32K x 8	Banks 0 & 1	(1) 16K x 4	(1) 32K x 8

CPU JUMPER CONFIGURATION
CPU	Jumper W10	Jumper W11	Jumper W14
80486DX	pins 1 & 2 closed	pins 1 & 2 and 3 & 4 closed	open
80487SX	pins 2 & 3 closed	pins 1 & 2 and 3 & 4 closed	closed
80486SX	open	pins 2 & 3 closed	closed
Note:The location of W14 is unknown.

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2	Bank 3	Jumpers W12,W13,W15,W16
1MB	(4) 256K x 9	NONE	NONE	NONE	pins 1 & 2 closed
1MB	NONE	NONE	(1) 256K x 36	NONE	pins 2 & 3 closed
2MB	(4) 256K x 9	(4) 256K x 9	NONE	NONE	pins 1 & 2 closed
2MB	NONE	NONE	(1) 256K x 36	(1) 256K x 36	pins 2 & 3 closed
3MB	(4) 256K x 9	(4) 256K x 9	(1) 256K x 36	NONE	pins 1 & 2 closed
4MB	(4) 256K x 9	(4) 256K x 9	(1) 256K x 36	(1) 256K x 36	pins 1 & 2 closed
4MB	(4) 1M x 9	NONE	NONE	NONE	pins 1 & 2 closed
4MB	NONE	NONE	(1) 1M x 36	NONE	pins 2 & 3 closed
5MB	(4) 256K x 9	(4) 1M x 9	NONE	NONE	pins 1 & 2 closed
8MB	(4) 1M x 9	(4) 1M x 9	NONE	NONE	pins 1 & 2 closed
8MB	NONE	NONE	(1) 1M x 36	(1) 1M x 36	pins 2 & 3 closed
12MB	(4) 1M x 9	(4) 1M x 9	(1) 1M x 36	NONE	pins 1 & 2 closed
16MB	(4) 1M x 9	(4) 1M x 9	(1) 1M x 36	(1) 1M x 36	pins 1 & 2 closed
16MB	(4) 4M x 9	NONE	NONE	NONE	pins 1 & 2 closed
16MB	NONE	NONE	(1) 4M x 36	NONE	pins 2 & 3 closed
20MB	(4) 1M x 9	(4) 4M x 9	NONE	NONE	pins 1 & 2 closed
32MB	(4) 4M x 9	(4) 4M x 9	NONE	NONE	pins 1 & 2 closed
32MB	NONE	NONE	(1) 4M x 36	(1) 4M x 36	pins 2 & 3 closed
48MB	(4) 4M x 9	(4) 4M x 9	(1) 4M x 36	NONE	pins 1 & 2 closed
64MB	(4) 4M x 9	(4) 4M x 9	(1) 4M x 36	(1) 4M x 36	pins 1 & 2 closed
Note:The locations of jumpers W12, W13, W15,and W16 are unknown.