SCI SYSTEMS, INC.
SCI 486SX/DX SYSTEM BOARD
Processor |
80486SX/80486DX |
Processor Speed |
25/33MHz |
Chip Set |
OPTI |
Max. Onboard DRAM |
64MB |
Cache |
64/256KB |
BIOS |
Unidentified |
Dimensions |
330mm x 218mm |
I/O Options |
Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial ports (2), VGA port |
NPU Options |
None |
CONNECTIONS | |||
Purpose |
Location |
Purpose |
Location |
PS/2 mouse port |
J1 |
IDE interface LED |
J23 |
IDE interface |
J5 |
Reset switch |
J24 |
Floppy drive interface |
J6 |
Speaker |
J25 |
Parallel port |
J8 |
Power LED & keylock |
J26 |
Serial port 2 |
J9 |
VGA port |
J27 |
Serial port 1 |
J10 |
USER CONFIGURABLE SETTINGS | |||
Function |
Jumper/Switch |
Position | |
» |
Monitor type select color |
W1 |
pins 1 & 2 closed |
Monitor type select monochrome |
W1 |
pins 2 & 3 closed | |
» |
CMOS memory normal operation |
W2 |
pins 1 & 2 closed |
CMOS memory clear |
W2 |
pins 2 & 3 closed | |
» |
SYSCLK enabled |
W3 |
pins 2 & 3 closed |
SYSCLK/2 enabled |
W3 |
pins 1 & 2 closed | |
» |
On board VGA enabled |
W10 |
pins 1 & 2 closed |
On board VGA disabled |
W10 |
pins 2 & 3 closed | |
» |
Video horizontal scan rate select 31.5 kHz |
SW1/5 |
On |
Video horizontal scan rate select 40kHz |
SW1/5 |
Off | |
» |
Video memory select 512KB |
SW1/6 |
On |
Video memory select 1MB |
SW1/6 |
Off |
DRAM CONFIGURATION | ||||
Size |
Bank 0 |
Bank 1 |
Bank 2 |
Bank 3 |
1MB |
(1) 256K x 36 |
NONE |
NONE |
NONE |
2MB |
(1) 256K x 36 |
(1) 256K x 36 |
NONE |
NONE |
4MB |
(1) 1M x 36 |
NONE |
NONE |
NONE |
5MB |
(1) 256K x 36 |
(1) 1M x 36 |
NONE |
NONE |
6MB |
(1) 256K x 36 |
(1) 256K x 36 |
(1) 1M x 36 |
NONE |
8MB |
(1) 1M x 36 |
(1) 1M x 36 |
NONE |
NONE |
9MB |
(1) 256K x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
NONE |
10MB |
(1) 256K x 36 |
(1) 256K x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
12MB |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
NONE |
13MB |
(1) 256K x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
16MB |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
16MB |
(1) 4M x 36 |
NONE |
NONE |
NONE |
20MB |
(1) 1M x 36 |
(1) 4M x 36 |
NONE |
NONE |
20MB |
(1) 4M x 36 |
(1) 1M x 36 |
NONE |
NONE |
24MB |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 4M x 36 |
NONE |
24MB |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
NONE |
24MB |
(1) 4M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
NONE |
28MB |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
28MB |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
28MB |
(1) 4M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
32MB |
(1) 4M x 36 |
(1) 4M x 36 |
NONE |
NONE |
36MB |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
NONE |
36MB |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
NONE |
36MB |
(1) 4M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
NONE |
40MB |
(1) 1M x 36 |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 4M x 36 |
40MB |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
40MB |
(1) 4M x 36 |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
40MB |
(1) 4M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
(1) 1M x 36 |
DRAM CONFIGURATION (CON’T) | ||||
Size |
Bank 0 |
Bank 1 |
Bank 2 |
Bank 3 |
48MB |
(1) 4M x 36 |
(1) 4M x 36 |
(1) 4M x 36 |
NONE |
52MB |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 4M x 36 |
(1) 4M x 36 |
52MB |
(1) 4M x 36 |
(1) 1M x 36 |
(1) 4M x 36 |
(1) 4M x 36 |
52MB |
(1) 4M x 36 |
(1) 4M x 36 |
(1) 4M x 36 |
(1) 1M x 36 |
64MB |
(1) 4M x 36 |
(1) 4M x 36 |
(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 |
(2) 16K x 4 |
256KB |
(4) 32K x 8 |
(4) 32K x 8 |
(2) 16K x 4 |
CACHE JUMPER CONFIGURATION | ||||
Size |
W4 |
W5 |
W9 |
W11 |
64KB |
pins 2 & 3 closed |
pins 2 & 3 closed |
pins 2 & 3 closed |
pins 2 & 3 closed |
256KB |
pins 1 & 2 closed |
pins 1 & 2 closed |
pins 1 & 2 closed |
pins 2 & 3 closed |
CPU TYPE CONFIGURATION | |||
Type |
W6 |
W7 |
W8 |
486SX |
pins 2 & 3 closed |
pins 2 & 3 closed |
N/A |
487SX |
pins 1 & 2 closed |
pins 1 & 2 closed |
pins 1 & 2 closed |
486DX |
pins 1 & 2 closed |
pins 1 & 2 closed |
pins 2 & 3 closed |
VIDEO CONFIGURATION (800 X 600) | |||
Refresh rate |
SW1/1 |
SW1/2 | |
» |
60Hz |
Off |
On |
56Hz |
Off |
Off | |
56Hz |
On |
On | |
72Hz |
On |
Off |
VIDEO CONFIGURATION (1024 X 768) | |||
Refresh rate |
SW1/3 |
SW1/4 | |
» |
Interlaced |
Off |
Off |
60Hz |
Off |
On | |
70Hz |
On |
Off | |
72Hz |
On |
On |
VIDEO MEMORY CONFIGURATION | ||
Size |
Bank 0 |
Bank 1 |
512KB |
(4) 256K x 4 |
NONE |
1MB |
(4) 256K x 4 |
(4) 256K x 4 |
Note: Bank 0 is factory installed and is not configurable. |