CLASSIC R Motherboard Settings and Configuration

Processor	80486SX/80486DX/80486DX2
Processor Speed	25/33/50(internal)/66(internal)MHz
Chip Set	VLSI
Max. Onboard DRAM	32MB
Cache	64/128/256KB
BIOS	Phoenix
Dimensions	330mm x 218mm
I/O Options	Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial ports (2), VESA feature connector, VGA port, riser slot
NPU Options	None

CONNECTIONS
Purpose	Location	Purpose	Location
VGA port	J1	Chassis fan power	J26
Parallel port	J2	IDE interface LED	J29
Serial port 2	J3	Power LED & keylock	J30
Serial port 1	J4	Reset switch	J31
PS/2 mouse port	J5	Chassis fan power	J32
VESA feature connector	J10	Speaker	J33
IDE interface	J14	Riser slot	SL1
Floppy drive interface	J15

USER CONFIGURABLE SETTINGS
Function		Jumper	Position
»	12v to flash BIOS enabled	J12	pins 1 & 2 closed
	12v to flash BIOS disabled	J12	pins 2 & 3 closed
»	Flash BIOS recovery mode disabled	J13	pins 1 & 2 closed
	Flash BIOS recovery mode enabled	J13	pins 2 & 3 closed
»	On board video enabled	J16	pins 1 & 2 closed
	On board video disabled	J16	pins 2 & 3 closed
»	Floppy drive write protect enabled	J17	pins 2 & 3 closed
	Floppy drive write protect disabled	J17	pins 1 & 2 closed
»	Password enabled	J20	pins 2 & 3 closed
	Password clear	J20	pins 1 & 2 closed
»	CMOS access enabled	J21	pins 1 & 2 closed
	CMOS access disabled	J21	pins 2 & 3 closed
»	CMOS memory normal operation	J28	Closed
	CMOS memory clear	J28	Open
Note: The location of the above jumpers are unidentified.

DRAM CONFIGURATION
Size	Bank 0	Bank 1
2MB	(1) 512K x 36	NONE
4MB	(1) 512K x 36	(1) 512K x 36
4MB	(1) 1M x 36	NONE
6MB	(1) 512K x 36	(1) 1M x 36
6MB	(1) 1M x 36	(1) 512K x 36
8MB	(1) 1M x 36	(1) 1M x 36
8MB	(1) 2M x 36	NONE
10MB	(1) 512K x 36	(1) 2M x 36
10MB	(1) 2M x 36	(1) 512K x 36
12MB	(1) 1M x 36	(1) 2M x 36
12MB	(1) 2M x 36	(1) 1M x 36
16MB	(1) 2M x 36	(1) 2M x 36
16MB	(1) 4M x 36	NONE
18MB	(1) 512K x 36	(1) 4M x 36
18MB	(1) 4M x 36	(1) 512K x 36
20MB	(1) 1M x 36	(1) 4M x 36
20MB	(1) 4M x 36	(1) 1M x 36
24MB	(1) 2M x 36	(1) 4M x 36
24MB	(1) 4M x 36	(1) 2M x 36
32MB	(1) 4M x 36	(1) 4M x 36

CACHE CONFIGURATION
Size	Bank 0	Bank 1	TAG
64KB	(4) 8K x 8	(4) 8K x 8	(1) 8K x 8
128KB	(4) 32K x 8	NONE	(1) 8K x 8
256KB	(4) 32K x 8	(4) 32K x 8	(1) 32K x 8
Note: The orientation of Banks 0 & 1 and TAG is unidentified.

CACHE JUMPER CONFIGURATION
Size	J11 pins 1 & 2	J11 pins 3 & 4	J11 pins 5 & 6	J11 pins 7 & 8
64KB	Open	Open	Open	Open
128KB	Closed	Open	Closed	Open
256KB	Closed	Closed	Open	Closed
Note: The location of J11 is unidentified.

CPU TYPE CONFIGURATION
Type	J22	J23	j24	j25
80486SX (PQFP)	pins 2 & 3 closed	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
80486SX (PGA)	pins 1 & 2 closed	pins 2 & 3 closed	pins 2 & 3 closed	pins 2 & 3 closed
80486DX	pins 2 & 3 closed	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
80486DX2	pins 2 & 3 closed	pins 1 & 2 closed	pins 1 & 2 closed	pins 1 & 2 closed
Note: The locations of J22, J23, J24 & J25 are unidentified. The location of the PQFP socket is unidentified.

CPU SPEED CONFIGURATION
Speed	J18	J19
25MHz	pins 1 & 2 closed	pins 1 & 2 closed
33MHz	pins 1 & 2 closed	pins 2 & 3 closed
50iMHz	pins 1 & 2 closed	pins 1 & 2 closed
66iMHz	pins 1 & 2 closed	pins 2 & 3 closed
Note: The locations of J18 & J19 are unidentified.

VRAM CONFIGURATION
Size	Bank 0	Bank 1
512KB	512KB	NONE
1MB	512KB	(4) 256K x 4
Note: Bank 0 is factory installed and is not configurable. The location is unidentified.