
PC BRAND

486/25C CACHE MAINBOARD

(MYSTERY MACHINE)

Processor         80486SX
Processor Speed   25MHz
Chip Set          OPTI
Max. Onboard DRAM 16MB
Cache             128KB (on external cache card)
BIOS              AMI
Dimensions        330mm x 218mm
I/O Options       External cache card
NPU Options       4167

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  External battery            J1       Turbo switch                J9

  Power LED & keylock         J6       Turbo LED                   J10

  Speaker                     J7       External cache slot         SL1

  Reset switch                J8

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Battery type select internal             J1           pins 2 & 3
                                                              closed

      Battery type select external             J1             Closed

     Monitor type select monochrome           J2              Open

      Monitor type select color                J2             Closed

     Factory configured - do not              J3              N/A
      alter

                            DRAM CONFIGURATION

     Size         Bank 0         Bank 1         Bank 2         Bank 3

     1MB        (4) 256K x 9      NONE           NONE           NONE

     2MB        (4) 256K x 9   (4) 256K x 9      NONE           NONE

     3MB        (4) 256K x 9   (4) 256K x 9   (4) 256K x 9      NONE

     4MB        (4) 256K x 9   (4) 256K x 9   (4) 256K x 9  (4) 256K x 9

     4MB        (4) 1M x 9        NONE           NONE           NONE

     5MB        (4) 256K x 9   (4) 1M x 9        NONE           NONE

     5MB        (4) 1M x 9     (4) 256K x 9      NONE           NONE

     6MB        (4) 256K x 9   (4) 256K x 9   (4) 1M x 9        NONE

     6MB        (4) 256K x 9   (4) 1M x 9     (4) 256K x 9      NONE

     6MB        (4) 1M x 9     (4) 256K x 9   (4) 256K x 9      NONE

     7MB        (4) 256K x 9   (4) 256K x 9   (4) 1M x 9    (4) 256K x 9

     7MB        (4) 256K x 9   (4) 1M x 9     (4) 256K x 9  (4) 256K x 9

     7MB        (4) 1M x 9     (4) 256K x 9   (4) 256K x 9  (4) 256K x 9

     8MB        (4) 1M x 9     (4) 1M x 9        NONE           NONE

     9MB        (4) 256K x 9   (4) 1M x 9     (4) 1M x 9        NONE

     9MB        (4) 1M x 9     (4) 1M x 9     (4) 256K x 9      NONE

     9MB        (4) 1M x 9     (4) 256K x 9   (4) 1M x 9        NONE

     10MB       (4) 256K x 9   (4) 256K x 9   (4) 1M x 9     (4) 1M x 9

     10MB       (4) 256K x 9   (4) 1M x 9     (4) 1M x 9    (4) 256K x 9

     10MB       (4) 1M x 9     (4) 1M x 9     (4) 256K x 9  (4) 256K x 9

     10MB       (4) 1M x 9     (4) 256K x 9   (4) 1M x 9    (4) 256K x 9

     12MB       (4) 1M x 9     (4) 1M x 9     (4) 1M x 9        NONE

     13MB       (4) 256K x 9   (4) 1M x 9     (4) 1M x 9     (4) 1M x 9

     13MB       (4) 1M x 9     (4) 1M x 9     (4) 1M x 9    (4) 256K x 9

     13MB       (4) 1M x 9     (4) 256K x 9   (4) 1M x 9     (4) 1M x 9

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

        CACHE CONFIGURATION

       Size              SL1

      128KB        Card installed

                  CACHE JUMPER CONFIGURATION

       Setting                J4                   J5

     Cache mode        pins 1 & 2 closed   pins 1 & 2 closed

     Burst mode        pins 2 & 3 closed   pins 2 & 3 closed

