PERSONAL COMPUTER SYTEMS SYSTEM BOARD Motherboard Settings and Configuration

Processor	80386SX/80486SX/80487SX (depends on CPU board installed)
Processor Speed	20/33MHz
Chip Set	Unidentified
Max. Onboard DRAM	32MB
Cache	32/128KB (depends on CPU board installed)
BIOS	Unidentified
Dimensions	254mm x 218mm
I/O Options	Parallel port, serial ports (2), VGA port, VGA feature connector, floppy drive interface, IDE interface, riser slot, CPU slot
NPU Options	80387SX

CONNECTIONS
Purpose	Location	Purpose	Location
VGA port	J2	External battery	J17
Serial port 1	J3	Turbo LED	J25
Serial port 2	J4	IDE interface LED	J26
Parallel port	J5	Auxiliary speaker	J27
VGA feature connector	J7	Reset switch	S1
Floppy drive interface	J11	Riser Card	SL1
IDE interface	J12	CPU slot	SL2
Speaker	J16

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	256KB - 640KB memory enabled	J6	pins 1 & 2 closed
	256KB - 640KB memory disabled	J6	pins 1 & 2 open
»	512KB - 640KB memory enabled	J6	pins 3 & 4 closed
	512KB - 640KB memory disabled	J6	pins 3 & 4 open
»	Security disabled	J6	pins 5 & 6 closed
	Security enabled	J6	pins 5 & 6 open
»	VGA mode select PS/2	J10	pins 5 & 6 closed
	VGA mode select AT	J10	pins 5 & 6 open
»	Monitor timing select any monitor timing	J10	pins 7 & 8 open
	Monitor timing select Multi Sync 1 timing	J10	pins 7 & 8 closed
»	Factory configured - do not alter	J13	N/A
»	Factory configured - do not alter	J28	N/A

DRAM CONFIGURATION
Size	Bank 0	Bank 1	Bank 2	Bank 3
512KB	(2) 256K x 9	NONE	NONE	NONE
1MB	(2) 256K x 9	(2) 256K x 9	NONE	NONE
1.5MB	(2) 256K x 9	(2) 256K x 9	(2) 256K x 9	NONE
2MB	(2) 256K x 9	(2) 256K x 9	(2) 256K x 9	(2) 256K x 9
2MB	(2) 1M x 9	NONE	NONE	NONE
2.5MB	(2) 1M x 9	(2) 256K x 9	NONE	NONE
3MB	(2) 256K x 9	(2) 256K x 9	(2) 1M x 9	NONE
3.5MB	(2) 256K x 9	(2) 256K x 9	(2) 1M x 9	(2) 256K x 9
4MB	(2) 1M x 9	(2) 1M x 9	NONE	NONE
4.5MB	(2) 1M x 9	(2) 1M x 9	(2) 256K x 9	NONE
5MB	(2) 1M x 9	(2) 1M x 9	(2) 256K x 9	(2) 256K x 9
6MB	(2) 1M x 9	(2) 1M x 9	(2) 1M x 9	NONE
6.5MB	(2) 1M x 9	(2) 1M x 9	(2) 1M x 9	(2) 256K x 9
8MB	(2) 1M x 9	(2) 1M x 9	(2) 1M x 9	(2) 1M x 9
8MB	(2) 4M x 9	NONE	NONE	NONE
8.5MB	(2) 4M x 9	(2) 256K x 9	NONE	NONE
9MB	(2) 256K x 9	(2) 256K x 9	(2) 4M x 9	NONE
10MB	(2) 4M x 9	(2) 1M x 9	NONE	NONE

DRAM CONFIGURATION (CON’T)
Size	Bank 0	Bank 1	Bank 2	Bank 3
12MB	(2) 4M x 9	(2) 1M x 9	(2) 1M x 9	NONE
14MB	(2) 1M x 9	(2) 1M x 9	(2) 4M x 9	(2) 1M x 9
16MB	(2) 4M x 9	(2) 4M x 9	NONE	NONE
16.5MB	(2) 4M x 9	(2) 4M x 9	(2) 256K x 9	NONE
17MB	(2) 4M x 9	(2) 4M x 9	(2) 256K x 9	(2) 256K x 9
18MB	(2) 4M x 9	(2) 4M x 9	(2) 1M x 9	NONE
20MB	(2) 4M x 9	(2) 4M x 9	(2) 1M x 9	(2) 1M x 9
24MB	(2) 4M x 9	(2) 4M x 9	(2) 4M x 9	NONE
32MB	(2) 4M x 9	(2) 4M x 9	(2) 4M x 9	(2) 4M x 9

VRAM CONFIGURATION
Size	Bank 0	Bank 1
512KB	512KB	NONE
1MB	512KB	512KB

CACHE CONFIGURATION
Size	Bank 0	Bank 1
32KB	(2) 8K x 8	(2) 8K x 8
128KB	(2) 32K x 8	(2) 32K x 8

CACHE JUMPER CONFIGURATION
Size	JP1
32KB	pins 1 & 2 closed
128KB	pins 3 & 4 closed

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	Factory configured - do not alter	JP1	N/A

CPU TYPE CONFIGURATION
Type	JP1	JP2
80486SX-20	Open	Closed
80486SX-33	Closed	Open
80487SX-20	Closed	Open