OPTimum EISA486SD - 6A5B1 Motherboard Settings and Configuration

Processor	80486SX/80487SX/80486DX
Processor Speed	20/25/33/40/50MHz
Chip Set	OPTI
Max. Onboard DRAM	32MB
SRAM Cache	64/128/256/512KB
BIOS	AMI
Dimensions	330mm x 218mm
I/O Options	None
NPU Options	4167

CONNECTIONS
Purpose	Location	Purpose	Location
Speaker	J4	Reset switch	S9
Power LED & keylock	J5

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Monitor type select color	JP4	closed
	Monitor type select monochrome	JP4	open
	CPU speed select iOCS/1	JP8	pins 1 & 2 closed
	CPU speed select iOCS/2	JP8	pins 2 & 3 closed

DRAM CONFIGURATION
Size	Bank 0	Bank 1
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

CPU TYPE CONFIGURATION
CPU	JP7	JP9
80486DX	pins 1 & 2 and 3 & 4 closed	pins 2 & 3 closed
80487SX	pins 1 & 2 and 3 & 4 closed	pins 1 & 2 closed
80486SX	pins 2 & 3 closed	open

CPU SPEED CONFIGURATION
Speed	JP1	JP2	JP3	JP6
50MHz	closed	closed	pins 1 & 2 closed	open
40MHz	open	closed	pins 1 & 2 closed	open
33MHz	closed	open	pins 1 & 2 closed	open
25MHz	open	open	pins 1 & 2 closed	open
20MHz	open	open	pins 2 & 3 closed	closed

SRAM JUMPER CONFIGURATION
Size	JP5	JP10	JP11	JP12	JP13	JP14	JP15
64KB	pins 2 & 3 closed	open	open	open	open	open	open
128KB	pins 1 & 2 closed	open	open	closed	open	closed	open
256KB	pins 2 & 3 closed	open	closed	closed	closed	closed	open
512KB	pins 1 & 2 closed	closed	closed	closed	closed	closed	closed

SRAM CONFIGURATION
Size	Cache SRAM	Location	TAG (U50)	TAG (U51)	Dirty bit (U64)
64KB	(8) 8K x 8	Banks 0 & 1	(1) 8K x 8	N/A	(1) 16K x 1
128KB	(4) 32K x 8	Bank 0	(1) 8K x 8	N/A	(1) 16K x 1
256KB	(8) 32K x 8	Banks 0 & 1	(1) 8K x 8	(1) 8K x 8	(1) 16K x 1
512KB	(4) 128K x 8	Bank 0	(1) 32K x 8	N/A	(1) 64K x 1
Note:Dirty bit (U64) can always accommodate (1) 64K x 1 for any of the four configurations.