
UNIDENTIFIED

COMPASS-486DX

Processor         80486SX/80487SX/80486DX/80486DX2
Processor Speed   25/33/50(internal)/66(internal)MHz
Chip Set          OPTI
Max. Onboard DRAM 32MB
Cache             64/128/256KB
BIOS              AMI
Dimensions        254mm x 218mm
I/O Options       None
NPU Options       None

[Image]

                                CONNECTIONS

  Purpose                   Location    Purpose                  Location

  External battery             J9       Turbo switch              JP10

  Speaker                     J18       Turbo LED                 JP11

  Power LED & keylock         J19       Reset switch               SW1

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     CMOS memory normal operation            JP1           pins 2 & 3
                                                              closed

      CMOS memory clear                       JP1           pins 1 & 2
                                                              closed

      Monitor type select monochrome          JP2              Open

      Monitor type select color               JP2             Closed

      Clock phase select double phase         JP4           pins 1 & 2
                                                              closed

      Clock phase select single phase         JP4           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

      8MB         (4) 1M x 9      (4) 1M x 9

      16MB        (4) 4M x 9         NONE

      32MB        (4) 4M x 9      (4) 4M x 9

                           CACHE CONFIGURATION

     Size          Bank 0         Bank 1         TAG 0          TAG 1

     64KB        (4) 8K x 8     (4) 8K x 8       NONE        (1) 8K x 8

     128KB      (4) 32K x 8        NONE          NONE        (1) 8K x 8

     256KB      (4) 32K x 8    (4) 32K x 8    (1) 8K x 8     (1) 8K x 8

                     CACHE JUMPER CONFIGURATION

   Size      JP3      JP5       JP6       JP7      JP8       JP9

   64KB     2 & 3     Open     Open      Open      Open      Open

  128KB     1 & 2     Open     Open      Closed   Closed    Closed

  256KB     2 & 3    Closed    Closed    Closed   Closed    Closed

  Note: Pins designated should be in the closed position

                          CPU TYPE CONFIGURATION

       Type               JP12               JP13              JP14

      80486SX           pins 2 & 3           Open              Open
                         closed

      80487SX           pins 1 & 2        pins 2 & 3          Closed
                         closed             closed

      80486DX           pins 1 & 2        pins 1 & 2          Closed
                         closed             closed

     80486DX2           pins 1 & 2        pins 1 & 2          Closed
                         closed             closed

          MISCELLANEOUS TECHNICAL NOTE

  Note: The location of pin 1 is unidentified.

