SOYO COMPUTER CO., LTD.
486 VESA MAINBOARD
| 
 Processor  | 
 CX486S/80486SX/CX486S2/80487SX/CX486DX/80486DX/CX486DX2/ 80486DX2/Pentium Overdrive  | 
| 
 Processor Speed  | 
 25/33/40/50(internal)/50/66(internal)MHz  | 
| 
 Chip Set  | 
 ALI  | 
| 
 Max. Onboard DRAM  | 
 128MB  | 
| 
 Cache  | 
 64/128/256KB  | 
| 
 BIOS  | 
 AMI  | 
| 
 Dimensions  | 
 254mm x 220mm  | 
| 
 I/O Options  | 
 32-bit VESA local bus slots (2)  | 
| 
 NPU Options  | 
 None  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 Power LED & keylock  | 
 J17  | 
 Turbo switch  | 
 J21  | 
| 
 Speaker  | 
 J18  | 
 Turbo LED  | 
 J22  | 
| 
 Reset switch  | 
 J19  | 
 32-bit VESA local bus slots  | 
 SL1 & SL2  | 
| 
 External battery  | 
 J20  | ||
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Jumper  | 
 Position  | |
| 
 »  | 
 Monitor type select monochrome  | 
 JP3  | 
 Open  | 
| 
 Monitor type select color  | 
 JP3  | 
 Closed  | |
| 
 »  | 
 CMOS memory normal operation  | 
 JP5  | 
 pins 1 & 2 closed  | 
| 
 CMOS memory clear  | 
 JP5  | 
 pins 2 & 3 closed  | |
| 
 »  | 
 Factory configured - do not alter  | 
 JP18  | 
 Open  | 
| 
 »  | 
 Factory configured - do not alter  | 
 JP19  | 
 Open  | 
| 
 »  | 
 Battery type select internal  | 
 JP20  | 
 pins 1 & 2 closed  | 
| 
 Battery type select external  | 
 JP20  | 
 pins 2 & 3 closed  | |
| 
 »  | 
 CPU type select PGA  | 
 JP30  | 
 Closed  | 
| 
 CPU type select PQFP  | 
 JP30  | 
 Open  | |
| 
 DRAM CONFIGURATION  | ||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
| 
 1MB  | 
 (4) 256K x 9  | 
 NONE  | 
| 
 2MB  | 
 (4) 256K x 9  | 
 (4) 256K x 9  | 
| 
 4MB  | 
 (4) 1M x 9  | 
 NONE  | 
| 
 5MB  | 
 (4) 256K x 9  | 
 (4) 1M x 9  | 
| 
 8MB  | 
 (4) 1M x 9  | 
 (4) 1M x 9  | 
| 
 16MB  | 
 (4) 4M x 9  | 
 NONE  | 
| 
 17MB  | 
 (4) 256K x 9  | 
 (4) 4M x 9  | 
| 
 20MB  | 
 (4) 1M x 9  | 
 (4) 4M x 9  | 
| 
 32MB  | 
 (4) 4M x 9  | 
 (4) 4M x 9  | 
| 
 64MB  | 
 (4) 16M x 9  | 
 NONE  | 
| 
 68MB  | 
 (4) 1M x 9  | 
 (4) 16M x 9  | 
| 
 80MB  | 
 (4) 4M x 9  | 
 (4) 16M x 9  | 
| 
 128MB  | 
 (4) 16M x 9  | 
 (4) 16M x 9  | 
| 
 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  | 
| 
 CACHE JUMPER CONFIGURATION  | |||
| 
 Size  | 
 JP16  | 
 JP22  | 
 JP23  | 
| 
 64KB  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 128KB  | 
 N/A  | 
 N/A  | 
 N/A  | 
| 
 256KB  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
| 
 Note: The jumper settings for 64KB & 128KB are unavailable from manufacturer.  | |||
| 
 CPU TYPE CONFIGURATION  | ||||||
| 
 Type  | 
 JP1  | 
 JP6  | 
 JP7  | 
 JP8  | 
 JP9  | 
 JP10  | 
| 
 CX486S  | 
 1 & 2  | 
 2 & 3  | 
 2 & 3  | 
 1 & 2  | 
 Open  | 
 Open  | 
| 
 80486SX  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
 1 & 2  | 
 Closed  | 
 Closed  | 
| 
 CX486S2  | 
 1 & 2  | 
 2 & 3  | 
 2 & 3  | 
 1 & 2  | 
 Open  | 
 Open  | 
| 
 80487SX  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
 2 & 3  | 
 Closed  | 
 Closed  | 
| 
 CX486DX  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
 2 & 3  | 
 Closed  | 
 Closed  | 
| 
 CX486DX2  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
 2 & 3  | 
 Closed  | 
 Closed  | 
| 
 80486DX/DX2  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
 2 & 3  | 
 Closed  | 
 Closed  | 
| 
 Pentium Overdrive  | 
 2 & 3  | 
 2 & 3  | 
 1 & 2  | 
 2 & 3  | 
 Closed  | 
 Closed  | 
| 
 Note: Pins designated should be in the closed position.  | ||||||
| 
 CPU TYPE CONFIGURATION (CON’T)  | ||||||
| 
 Type  | 
 JP11  | 
 JP12  | 
 JP13  | 
 JP14  | 
 JP17  | 
 JP31  | 
| 
 CX486S  | 
 3 & 4  | 
 2 & 3  | 
 1 & 2  | 
 2 & 3  | 
 2 & 3  | 
 Open  | 
| 
 80486SX  | 
 Open  | 
 1 & 2  | 
 1 & 2  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
| 
 CX486S2  | 
 3 & 4  | 
 2 & 3  | 
 1 & 2  | 
 2 & 3  | 
 2 & 3  | 
 Closed  | 
| 
 80487SX  | 
 1 & 2  | 
 1 & 2  | 
 1 & 2  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
| 
 CX486DX  | 
 2 & 3  | 
 1 & 2  | 
 1 & 2  | 
 2 & 3  | 
 1 & 2  | 
 Open  | 
| 
 CX486DX2  | 
 2 & 3  | 
 1 & 2  | 
 1 & 2  | 
 2 & 3  | 
 1 & 2  | 
 Closed  | 
| 
 80486DX/DX2  | 
 2 & 3  | 
 1 & 2  | 
 1 & 2  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
| 
 Pentium Overdrive  | 
 1 & 2  | 
 1 & 2  | 
 2 & 3  | 
 1 & 2  | 
 1 & 2  | 
 Open  | 
| 
 Note: Pins designated should be in the closed position.  | ||||||
| 
 CPU SPEED CONFIGURATION  | ||||
| 
 Speed  | 
 JP24  | 
 JP25  | 
 JP26  | 
 JP27  | 
| 
 25MHz  | 
 Open  | 
 Open  | 
 Closed  | 
 Open  | 
| 
 33MHz  | 
 Closed  | 
 Open  | 
 Closed  | 
 Closed  | 
| 
 40MHz  | 
 Open  | 
 Closed  | 
 Open  | 
 Open  | 
| 
 50iMHz  | 
 Open  | 
 Open  | 
 Closed  | 
 Open  | 
| 
 50MHz  | 
 Open  | 
 Open  | 
 Closed  | 
 Open  | 
| 
 66iMHz  | 
 Closed  | 
 Open  | 
 Closed  | 
 Closed  | 
| 
 CPU CLOCK SPEED CONFIGURATION  | |||
| 
 Speed  | 
 JP15  | 
 JP21  | 
 JP33  | 
| 
 25MHz  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
| 
 33MHz  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
| 
 40MHz  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
| 
 50iMHz  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
| 
 50MHz  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
| 
 66iMHz  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
| 
 VESA WAIT STATE CONFIGURATION  | |
| 
 Wait states  | 
 JP28  | 
| 
 0 wait states  | 
 pins 1 & 2 closed  | 
| 
 1 wait state  | 
 pins 2 & 3 closed  | 
| 
 BUS SPEED CONFIGURATION  | |
| 
 CPU speed  | 
 JP29  | 
| 
 <= 33MHz  | 
 pins 1 & 2 closed  | 
| 
 > 33MHz  | 
 pins 2 & 3 closed  |