UNIDENTIFIED
50/33/25/20MHZ MAINBOARD
| 
 Processor  | 
 80486SX/80487SX/80486DX/80486DX2  | 
| 
 Processor Speed  | 
 20/25/33/40/50 (Internal) /50/66 (Internal)  | 
| 
 Chip Set  | 
 C & T  | 
| 
 Max. onboard DRAM  | 
 32MB  | 
| 
 Cache  | 
 64/128/256KB  | 
| 
 BIOS  | 
 AMI  | 
| 
 Dimensions  | 
 330mm x 218mm  | 
| 
 I/O Options  | 
 None  | 
| 
 NPU Options  | 
 None  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 Power LED & keylock  | 
 J17  | 
 External battery  | 
 J20  | 
| 
 Speaker  | 
 J18  | 
 Turbo switch  | 
 J21  | 
| 
 Reset switch  | 
 J19  | 
 Turbo LED  | 
 J22  | 
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Jumper/Switch  | 
 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  | |
| 
 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  | 
| 
 20MB  | 
 (4) 1M x 9  | 
 (4) 4M x 9  | 
| 
 32MB  | 
 (4) 4M x 9  | 
 (4) 4M x 9  | 
| 
 CACHE CONFIGURATION  | ||||
| 
 Size  | 
 Max Cachable  | 
 Bank 0  | 
 Bank 1  | 
 TAG  | 
| 
 64KB  | 
 16MB  | 
 (4) 8K x 8  | 
 (4) 8K x 8  | 
 (1) 8K x 8  | 
| 
 128KB  | 
 32MB  | 
 (4) 32K x 8  | 
 NONE  | 
 (1) 8K x 8  | 
| 
 256KB  | 
 64MB  | 
 (4) 32K x 8  | 
 (4) 32K x 8  | 
 (1) 32K x 8  | 
| 
 CACHE JUMPER CONFIGURATION  | ||
| 
 Size  | 
 JP24  | 
 JP25  | 
| 
 64KB  | 
 Open  | 
 Open  | 
| 
 128KB  | 
 Pins 1 & 2 closed  | 
 Pins 1 & 2 closed  | 
| 
 256KB  | 
 Pins 2 & 3 closed  | 
 Pins 2 & 3 closed  | 
| 
 CPU SPEED CONFIGURATION  | |
| 
 Speed  | 
 JP21  | 
| 
 80486SX/20MHz  | 
 Pins 5 & 6 closed  | 
| 
 80486SX/25MHz  | 
 Pins 1 & 2, 5 & 6 closed  | 
| 
 80486SX/33MHz  | 
 Pins 1 & 2, 3 & 4 closed  | 
| 
 80487SX/20MHz  | 
 Pins 5 & 6 closed  | 
| 
 80486DX/25MHz  | 
 Pins 1 & 2, 5 & 6 closed  | 
| 
 80486DX/33MHz  | 
 Pins 1 & 2, 3 & 4 closed  | 
| 
 80486DX/40MHz  | 
 Pins 5 & 6 closed  | 
| 
 80486DX/50MHz  | 
 Pins 3 & 4 closed  | 
| 
 80486DX2/50i MHz  | 
 Pins 1 & 2, 5 & 6 closed  | 
| 
 80486DX2/66i MHz  | 
 Pins 1 & 2, 3 & 4 closed  | 
| 
 CPU TYPE CONFIGURATION  | ||||
| 
 TYPE  | 
 JP9  | 
 JP11  | 
 JP12  | 
 JP13  | 
| 
 80486SX/20MHz  | 
 Pins 2 & 3 closed  | 
 Open  | 
 Pins 2 & 3 closed  | 
 Pins 2 & 3 closed  | 
| 
 80486SX/25MHz  | 
 Pins 1 & 2 closed  | 
 Open  | 
 Pins 2 & 3 closed  | 
 Pins 2 & 3 closed  | 
| 
 80486SX/33MHz  | 
 Pins 1 & 2 closed  | 
 Open  | 
 Pins 2 & 3 closed  | 
 Pins 2 & 3 closed  | 
| 
 80487SX/20MHz  | 
 Pins 2 & 3 closed  | 
 Closed  | 
 Pins 2 & 3 closed  | 
 Pins 1 & 2 closed  | 
| 
 80486DX/25MHz  | 
 Pins 1 & 2 closed  | 
 Closed  | 
 Pins 1 & 2 closed  | 
 Pins 1 & 2 closed  | 
| 
 80486DX/33MHz  | 
 Pins 1 & 2 closed  | 
 Closed  | 
 Pins 1 & 2 closed  | 
 Pins 1 & 2 closed  | 
| 
 80486DX/40MHz  | 
 Pins 1 & 2 closed  | 
 Closed  | 
 Pins 1 & 2 closed  | 
 Pins 1 & 2 closed  | 
| 
 80486DX/50MHz  | 
 Pins 1 & 2 closed  | 
 Closed  | 
 Pins 1 & 2 closed  | 
 Pins 1 & 2 closed  | 
| 
 80486DX2/50i MHz  | 
 Pins 1 & 2 closed  | 
 Closed  | 
 Pins 1 & 2 closed  | 
 Pins 1 & 2 closed  | 
| 
 80486DX2/66i MHz  | 
 Pins 1 & 2 closed  | 
 Closed  | 
 Pins 1 & 2 closed  | 
 Pins 1 & 2 closed  |