UNIDENTIFIED

5/486 MOTHERBOARD

Processor        80486SX/80487SX/80486DX/80486DX2/Pentium Overdrive
Processor Speed  25/33/40/50(internal)/50/66(internal)MHz
Chip Set         Unknown
Max. Onboard DRAM128MB
Cache            128/256KB
BIOS             AMI
Dimensions       330mm x 218mm
I/O Options      32-bit VESA local bus slots (3)
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                Location     Purpose                  Location

  External battery          J2        Power LED & keylock        JP123

  Reset switch             JP119      32-bit memory               S1
                                      expansion slot

  Turbo switch             JP120      32-bit memory               S2
                                      expansion slot

  Turbo LED                JP121      32-bit memory               S3
                                      expansion slot

  Speaker                  JP122

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

  »   Monitor type select color               JP31            Closed

      Monitor type select monochrome          JP31             Open

  »   CMOS memory normal operation            JP33          pins 1 & 2
                                                              closed

      CMOS memory clear                       JP33          pins 2 & 3
                                                              closed

  »   VESA clock normal                      JP118          pins 1 & 2
                                                              closed

      VESA clock adjusted                    JP118          pins 2 & 3
                                                              closed

                CPU SPEED

  Speed      JP34      JP35      JP36

  25MHz     Closed     Open     Closed

  33MHz     Closed    Closed     Open

  40MHz      Open      Open     Closed

  50iMHz    Closed     Open     Closed

  50MHz      Open     Closed     Open

  66iMHz    Closed    Closed     Open

                        CPU TYPE CONFIGURATION

               Type                               JP30

              80486SX                      pins 5 & 6 closed

              80487SX               pins 1 & 2, 4 & 5, 6 & 7 closed

              80486DX               pins 2 & 3, 4 & 5, 6 & 7 closed

             80486DX2               pins 2 & 3, 4 & 5, 6 & 7 closed

         Pentium Overdrive          pins 1 & 2, 4 & 5, 6 & 7 closed

                            CACHE CONFIGURATION

    Size        U51, U52,        U55, U56,       TAG           JP58
                U53, U54         U57, U58

    128KB      (4) 32K x 8         NONE        (1) 8K x      Pins 1 & 2
                                                  8           closed

    256KB      (4) 32K x 8     (4) 32K x 8      (1) 32K      Pins 2 & 3
                                                 x 8          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

  64MB      (4) 16M x 9         NONE

  65MB      (4) 16M x 9     (4) 256K x 9

  68MB      (4) 16M x 9      (4) 1M x 9

  80MB      (4) 16M x 9      (4) 4M x 9

  128MB     (4) 16M x 9      (4) 16M x 9