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 [Image] 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 W1 pins 2 & 3 monochrome 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 SW1/5 On select 31.5 kHz Video horizontal scan rate SW1/5 Off select 40kHz » 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 NONE NONE NONE 36 2MB (1) 256K x (1) 256K x NONE NONE 36 36 4MB (1) 1M x 36 NONE NONE NONE 5MB (1) 256K x (1) 1M x 36 NONE NONE 36 6MB (1) 256K x (1) 256K x (1) 1M x 36 NONE 36 36 8MB (1) 1M x 36 (1) 1M x 36 NONE NONE 9MB (1) 256K x (1) 1M x 36 (1) 1M x 36 NONE 36 10MB (1) 256K x (1) 256K x (1) 1M x 36 (1) 1M x 36 36 36 12MB (1) 1M x 36 (1) 1M x 36 (1) 1M x 36 NONE 13MB (1) 256K x (1) 1M x 36 (1) 1M x 36 (1) 1M x 36 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 pins 2 & 3 pins 2 & 3 pins 2 & 3 closed closed closed closed 256KB pins 1 & 2 pins 1 & 2 pins 1 & 2 pins 2 & 3 closed closed closed closed CPU TYPE CONFIGURATION Type W6 W7 W8 486SX pins 2 & 3 pins 2 & 3 N/A closed closed 487SX pins 1 & 2 pins 1 & 2 pins 1 & 2 closed closed closed 486DX pins 1 & 2 pins 1 & 2 pins 2 & 3 closed closed 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.