DIGITAL EQUIPMENT CORPORATION

VENTURIS 486 (VER. 2.0)

Device Type        Mainboard
Processor          AM486DX2/P24D/P24T
Processor Speed    25/33/40/50(internal)/66(internal)MHz
Chip Set           Unidentified
Video Chip Set     S3
Maximum Onboard    68MB
Memory
Maximum Video      1MB
Memory
Cache              128/256KB
BIOS               Phoenix
Dimensions         254mm x 218mm
I/O Options        Floppy drive interface, IDE interfaces (2), parallel
                   port, PS/2 mouse port, serial ports (2), VGA port,
                   riser slot
NPU Options        None

[Image]

                                CONNECTIONS

  Purpose                  Location   Purpose                    Location

  VGA port                   CN1      Floppy drive interface       CN6

  Serial port                CN2      IDE interface                CN7

  Serial port                CN3      IDE interface                CN8

  Parallel port              CN4      Riser slot                   SL1

  PS/2 mouse port            CN5

                        USER CONFIGURABLE SETTINGS

               Function                    Label           Position

  »   Write through enabled                 J1              Closed

      Write back enabled                    J1               Open

  »   Snoop select enabled                  J18        Pins 1 & 2 closed

      Snoop select disabled                 J18        Pins 2 & 3 closed

  »   On board video enabled                J19        Pins 2 & 3 closed

      On board video disabled               J19        Pins 1 & 2 closed

  »   Recovery mode normal operation        J21              Open

      Recovery mode enabled                 J21             Closed

  »   Password normal operation             J23              Open

      Password clear                        J23             Closed

  »   Factory configured - do not           SL2          Unidentified
      alter

                    SIMM CONFIGURATION

     Size          Bank 0         Bank 1        Bank 2

      4MB           4MB            None          None

      8MB           4MB        (1) 1M x 36       None

     12MB           4MB        (1) 1M x 36    (1) 1M x 36

     12MB           4MB        (1) 2M x 36       None

     16MB           4MB        (1) 1M x 36    (1) 2M x 36

     20MB           4MB        (1) 2M x 36    (1) 2M x 36

     20MB           4MB        (1) 4M x 36       None

     24MB           4MB        (1) 1M x 36    (1) 4M x 36

     28MB           4MB        (1) 2M x 36    (1) 4M x 36

     36MB           4MB        (1) 4M x 36    (1) 4M x 36

     36MB           4MB        (1) 8M x 36       None

                        SIMM CONFIGURATION (CON’T)

       Size             Bank 0             Bank 1             Bank 2

       40MB               4MB           (1) 1M x 36        (1) 8M x 36

       44MB               4MB           (1) 2M x 36        (1) 8M x 36

       52MB               4MB           (1) 4M x 36        (1) 8M x 36

       68MB               4MB           (1) 8M x 36        (1) 8M x 36

            Note: Bank 0 is factory installed and is not configurable.
            The location is unidentified.

                 CACHE CONFIGURATION

      Size             Bank 0           Bank 1

      128KB         (4) 32K x 8          None

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

  Note: The location of the cache is unidentified.

                  CACHE JUMPER CONFIGURATION

        Size                  J2                   J4

        128KB          Pins 1 & 2 closed   Pins 1 & 2 closed

        256KB          Pins 2 & 3 closed   Pins 2 & 3 closed

                        VIDEO MEMORY CONFIGURATION

  Note: Board is factory installed with 1MB cache. The location is
  unidentified.

     CPU SPEED SELECTION

  Speed      J14       J15

  25MHz      Open      Open

  33MHz      Open     Closed

  40MHz     Closed     Open

  50iMHz     Open      Open

  66iMHz     Open     Closed

                      CPU TYPE SELECTION

        Type                  J9                  J35

      AM486DX2         Pins 2 & 3 closed         Closed

        P24D           Pins 1 & 2 closed          Open

        P24T           Pins 1 & 2 closed          Open