
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

[Image]

                                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                 JP15             Open
      motherboard)

      Parity enabled (4 SIMM                  JP15            Closed
      motherboard)

     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      pins 2 & 3 closed    pins 2 & 3 closed
         configuration)

