
FOREX COMPUTER CORPORATION

FOREX 486 REV. VL2

Processor        80486SX/80487SX/80486DX/80486DX2/Pentium Overdrive
Processor Speed  20/25/33/40/50(internal)/50/66(internal)MHz
Chip Set         Forex
Max. Onboard DRAM32MB
Cache            64/128/256KB
BIOS             AMI
Dimensions       254mm x 220mm
I/O Options      32-bit VESA local bus slots (2)
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                  Location    Purpose                  Location

  Turbo LED                   J5       Reset switch                J9

  Speaker                     J6       External battery           JP1

  Turbo switch                J7       32-bit local bus         SL1 & SL2
                                       slots

  Power LED & keylock         J8

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     CMOS memory normal operation            JP6              Open

      CMOS memory clear                       JP6             Closed

     Factory configured - do not             JP9              Open
      alter

     CPU type select 80486                   JP12          pins 1 & 2
                                                              closed

      CPU type select Pentium                 JP12          pins 2 & 3
      Overdrive                                               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) 256K x 9    (4) 1M x 9

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

      16MB        (4) 4M x 9         NONE

      20MB        (4) 1M x 9      (4) 4M x 9

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

                            CACHE CONFIGURATION

       Size              Bank 0            Bank 1              TAG

       64KB            (4) 8K x 8        (4) 8K x 8         (1) 8K x 8

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

       256KB          (4) 32K x 8        (4) 32K x 8     (1) 16K/32K x 8

                        CACHE JUMPER CONFIGURATION

      Size              JP8A               JP8B               JP8C

      64KB            pins 2 & 3        pins 2 & 3      pins 2 & 3 closed
                       closed             closed

      128KB           pins 1 & 2        pins 1 & 2      pins 1 & 2 closed
                       closed             closed

      256KB           pins 1 & 2        pins 1 & 2      pins 1 & 2 closed
                       closed             closed

                          CPU TYPE CONFIGURATION

       Type            JP2           JP3           JP4            JP5

     80486SX        pins 2 & 3       Open          Open        pins 2 & 3
                      closed                                    closed

  80486SX/DX PQFP   pins 2 & 3    pins 2 & 3    pins 2 & 3     pins 2 & 3
                      closed        closed        closed        closed

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

   80486DX/DX2      pins 1 & 2    pins 1 & 2    pins 1 & 2     pins 1 & 2
                      closed        closed        closed        closed

      Pentium       pins 2 & 3    pins 1 & 2    pins 1 & 2     pins 2 & 3
    Overdrive         closed        closed        closed        closed

                          CPU SPEED CONFIGURATION

      Speed              JP7A              JP7B               JP7C

      20MHz           pins 2 & 3         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

      25MHz           pins 1 & 2         pins 2 & 3         pins 1 & 2
                        closed            closed             closed

      33MHz           pins 1 & 2         pins 1 & 2         pins 2 & 3
                        closed            closed             closed

      40MHz           pins 2 & 3         pins 2 & 3         pins 1 & 2
                        closed            closed             closed

      50iMHz          pins 1 & 2         pins 2 & 3         pins 1 & 2
                        closed            closed             closed

      50MHz           pins 2 & 3         pins 1 & 2         pins 2 & 3
                        closed            closed             closed

      66iMHz          pins 1 & 2         pins 1 & 2         pins 2 & 3
                        closed            closed             closed

      VESA WAIT STATE CONFIGURATION

     Wait states             JP10

    0 wait states     pins 1 & 2 closed

    1 wait state      pins 2 & 3 closed

         BUS SPEED CONFIGURATION

      CPU speed              JP11

      <= 33MHz        pins 1 & 2 closed

       > 33MHz        pins 2 & 3 closed

