LEADING TECHNOLOGY
386SX 25/33
| 
 Processor  | 
 80386SX  | 
| 
 Processor Speed  | 
 25/33MHz  | 
| 
 Chip Set  | 
 Unidentified  | 
| 
 Max. Onboard DRAM  | 
 4MB  | 
| 
 Cache  | 
 None  | 
| 
 BIOS  | 
 Unidentified  | 
| 
 Dimensions  | 
 330mm x 218mm  | 
| 
 I/O Options  | 
 Floppy drive interface, game port, IDE interface, parallel port, serial ports (2)  | 
| 
 NPU Options  | 
 80387SX  | 
| 
 CONNECTIONS  | |||
| 
 Purpose  | 
 Location  | 
 Purpose  | 
 Location  | 
| 
 Serial port 1  | 
 CN1  | 
 Reset switch  | 
 J2 pin 5  | 
| 
 Serial port 2  | 
 CN2  | 
 Ground  | 
 J2 pin 8  | 
| 
 Game port  | 
 CN3  | 
 Speaker  | 
 J8  | 
| 
 Parallel port  | 
 CN4  | 
 External battery  | 
 J9  | 
| 
 IDE interface LED  | 
 J1  | 
 IDE interface  | 
 J10  | 
| 
 Power LED & keylock  | 
 J2 pin 3  | 
 Floppy drive interface  | 
 J12  | 
| 
 Turbo switch  | 
 J2 pin 4  | 
 Riser Card  | 
 SL1  | 
| 
 USER CONFIGURABLE SETTINGS  | |||
| 
 Function  | 
 Jumper  | 
 Position  | |
| 
 »  | 
 NPU disabled  | 
 JP1  | 
 pins 1 & 2 closed  | 
| 
 NPU enabled  | 
 JP1  | 
 pins 2 & 3 closed  | |
| 
 »  | 
 External battery installed  | 
 JP6  | 
 pins 1 & 2 closed  | 
| 
 External battery not installed  | 
 JP6  | 
 pins 2 & 3 closed  | |
| 
 »  | 
 Parity disabled (3 SIMM motherboard)  | 
 JP15  | 
 Open  | 
| 
 Parity enabled (4 SIMM motherboard)  | 
 JP15  | 
 Closed  | |
| 
 »  | 
 Parallel port IRQ select IRQ7  | 
 JP34  | 
 pins 1 & 2 closed  | 
| 
 Parallel port IRQ select IRQ5  | 
 JP34  | 
 pins 2 & 3 closed  | |
| 
 »  | 
 IDE interface enabled  | 
 JP35  | 
 pins 2 & 3 closed  | 
| 
 IDE interface disabled  | 
 JP35  | 
 pins 1 & 2 closed  | |
| 
 »  | 
 Game port installed  | 
 JP42  | 
 pins 1 & 2 closed  | 
| 
 Game port not installed  | 
 JP42  | 
 pins 2 & 3 closed  | |
| 
 DRAM CONFIGURATION (WITH BANK 0A FACTORY INSTALLED)  | ||||
| 
 Size  | 
 Bank 0a  | 
 Bank 1  | 
 Bank 2  | 
 Bank 3  | 
| 
 1MB  | 
 (2) 1M x 4  | 
 NONE  | 
 NONE  | 
 NONE  | 
| 
 2MB  | 
 (2) 1M x 4  | 
 (1) 1M x 9  | 
 NONE  | 
 NONE  | 
| 
 4MB  | 
 (2) 1M x 4  | 
 (1) 1M x 9  | 
 (1) 1M x 9  | 
 (1) 1M x 9  | 
| 
 Note: This configuration is applicable only with Bank O factory installed. The mainboard is manufactured with either 4 SIMM banks or 3 SIMM banks and 2 DRAM banks. The 2 DRAM banks are factory installed and are not configurable.  | ||||
| 
 DRAM JUMPER CONFIGURATION (WITH BANK 0 FACTORY INSTALLED)  | |
| 
 Size  | 
 JP11-12, JP16, JP19-27  | 
| 
 1MB  | 
 pins 2 & 3 closed  | 
| 
 2MB  | 
 pins 2 & 3 closed  | 
| 
 4MB  | 
 pins 2 & 3 closed  | 
| 
 Note: This configuration is applicable only with Bank O factory installed.  | |
| 
 DRAM CONFIGURATION (WITH BANK 0 USER INSTALLED)  | ||||
| 
 Size  | 
 Bank 0  | 
 Bank 1  | 
 Bank 2  | 
 Bank 3  | 
| 
 2MB  | 
 (1) 1M x 9  | 
 (1) 1M x 9  | 
 NONE  | 
 NONE  | 
| 
 4MB  | 
 (1) 1M x 9  | 
 (1) 1M x 9  | 
 (1) 1M x 9  | 
 (1) 1M x 9  | 
| 
 Note: This configuration is applicable only with Bank O user installed.  | ||||
| 
 DRAM CONFIGURATION (WITH BANK 0 USER INSTALLED)  | |
| 
 Size  | 
 JP11-12, JP16, JP19-27  | 
| 
 2MB  | 
 pins 2 & 3 closed  | 
| 
 4MB  | 
 pins 2 & 3 closed  | 
| 
 Note: This configuration is applicable only with Bank O user installed.  | |
| 
 PARALLEL PORT CONFIGURATION  | ||
| 
 Parallel port  | 
 JP30  | 
 JP31  | 
| 
 LPT1 (0378h)  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 LPT1 (02BCh)  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
| 
 LPT2 (0278h)  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 SERIAL PORT 1 CONFIGURATION  | |||
| 
 Port 1  | 
 JP28  | 
 JP40  | |
| » | 
 COM 1  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 COM 3  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | |
| 
 COM 4  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | |
| 
 Disabled  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | |
| 
 SERIAL PORT 1 INTERRUPT CONFIGURATION  | |||
| 
 IRQ  | 
 JP32  | 
 JP39  | |
| » | 
 IRQ4  | 
 pins 1 & 2 closed  | 
 N/A  | 
| 
 IRQ3  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | |
| 
 SERIAL PORT 2 CONFIGURATION  | |||
| 
 Port 2  | 
 JP29  | 
 JP41  | |
| » | 
 COM 2  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 COM 3  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | |
| 
 COM 4  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | |
| 
 Disabled  | 
 pins 1 & 2 closed  | 
 pins 1 & 2 closed  | |
| 
 SERIAL PORT 2 INTERRUPT CONFIGURATION  | |||
| 
 IRQ  | 
 JP32  | 
 JP39  | |
| » | 
 IRQ3  | 
 N/A  | 
 pins 1 & 2 closed  | 
| 
 IRQ4  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | |
| 
 FLOPPY DRIVE CONFIGURATION  | ||
| 
 Type  | 
 JP37  | 
 JP44  | 
| 
 A = 3.5" & B = 5.25"  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  | 
| 
 A = 5.25" & B = 3.5"  | 
 pins 2 & 3 closed  | 
 pins 1 & 2 closed  | 
| 
 PAGE INTERLEAVE CONFIGURATION  | ||
| 
 Mode  | 
 JP14  | 
 JP18  | 
| 
 Disabled  | 
 pins 1 & 2 closed  | 
 pins 2 & 3 closed  | 
| 
 Enabled ( requires 4 SIMM configuration)  | 
 pins 2 & 3 closed  | 
 pins 2 & 3 closed  |