MYLEX CORPORATION
MSI/MDI486 System Board
| 
 Processor  | 
 80486SX/80487SX/80486DX  | 
| 
 Processor Speed  | 
 20/25/33MHz  | 
| 
 Chip Set  | 
 OPTI  | 
| 
 Max. Onboard DRAM  | 
 32MB  | 
| 
 Cache  | 
 64/256KB  | 
| 
 BIOS  | 
 Mylex  | 
| 
 Dimensions  | 
 330mm x 218mm  | 
| 
 I/O Options  | 
 Floppy drive interface, IDE interface, parallel port, serial ports (2)  | 
| 
 NPU Options  | 
 4167  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 External battery  | 
 BAT  | 
 Turbo LED  | 
 JP3  | 
| 
 Serial port 2  | 
 COM2  | 
 Reset switch  | 
 JP4  | 
| 
 Serial port 1  | 
 COM1  | 
 Speaker  | 
 JP5  | 
| 
 Floppy drive interface  | 
 FDD  | 
 IDE interface LED  | 
 JP6  | 
| 
 IDE interface  | 
 IDE  | 
 Parallel port  | 
 LPT  | 
| 
 Power LED & keylock  | 
 JP2  | ||
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Jumper  | 
 Position  | |
| » | 
 Monitor type select color  | 
 JP1  | 
 Closed  | 
| 
 Monitor type select monochrome  | 
 JP1  | 
 Open  | |
| » | 
 Parallel port select LPT1 interrupt IRQ7  | 
 JP19  | 
 pins 2 & 3 closed  | 
| 
 Parallel port select LPT2 interrupt IRQ5  | 
 JP19  | 
 pins 1 & 2 closed  | |
| » | 
 On-board interface ports enabled  | 
 JP20  | 
 pins 1 & 2 closed  | 
| 
 On-board interface ports disabled  | 
 JP20  | 
 pins 2 & 3 closed  | |
| » | 
 Battery type select internal  | 
 JP21  | 
 pins 2 & 3 closed  | 
| 
 Battery type select external  | 
 JP21  | 
 Open  | |
| 
 CMOS memory clear  | 
 JP21  | 
 pins 1 & 2 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) 1M x 9  | 
 (4) 256K x 9  | 
| 
 8MB  | 
 (4) 1M x 9  | 
 (4) 1M x 9  | 
| 
 16MB  | 
 (4) 4M x 9  | 
 NONE  | 
| 
 17MB  | 
 (4) 4M x 9  | 
 (4) 256K x 9  | 
| 
 20MB  | 
 (4) 4M x 9  | 
 (4) 1M x 9  | 
| 
 32MB  | 
 (4) 4M x 9  | 
 (4) 4M x 9  | 
| 
 CACHE CONFIGURATION  | |||
| 
 Size  | 
 Bank 0  | 
 TAG (U19)  | 
 TAG (U20)  | 
| 
 64KB  | 
 (8) 8K x 8  | 
 (1) 8K x 8  | 
 (1) 64K x 1  | 
| 
 256KB  | 
 (8) 32K x 8  | 
 (1) 32K x 8  | 
 (1) 64K x 1  | 
| 
 CACHE JUMPER CONFIGURATION  | ||||
| 
 Size  | 
 JP7  | 
 JP11  | 
 JP12  | 
 JP13  | 
| 
 64KB  | 
 Open  | 
 Open  | 
 Open  | 
 Open  | 
| 
 256KB  | 
 Closed  | 
 Closed  | 
 Open  | 
 Closed  | 
| 
 CPU TYPE CONFIGURATION  | |||
| 
 Type  | 
 JP8  | 
 JP9  | 
 JP10  | 
| 
 80486SX  | 
 Open  | 
 pins 2 & 3 closed  | 
 Open  | 
| 
 80487SX  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 Closed  | 
| 
 80486DX  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 Closed  | 
| 
 CPU SPEED CONFIGURATION  | ||||
| 
 Speed  | 
 JP14  | 
 JP15  | 
 JP16  | 
 JP17  | 
| 
 20MHz  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 25MHz  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 33MHz  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  |