
DIGITAL EQUIPMENT CORPORATION

DECPC LP

Device Type         Mainboard
Processor           80486SX/80486DX/80486DX2
Processor Speed     25/33/50(internal)/66(internal)MHz
Chip Set            OPTI
Video Chip Set      Unidentified
Maximum Onboard     64MB
Memory
Maximum Video       1MB
Memory
Cache               64KB
BIOS                Unidentified
Dimensions          254mm x 218mm
I/O Options         Floppy drive interface, IDE interface, parallel port,
                    PS/2 mouse port, serial ports (2), VGA feature
                    connector, VGA port, riser slot
NPU Options         None

[Image]

                                CONNECTIONS

  Purpose                 Location    Purpose                    Location

  VGA port                  CN1       IDE interface                CN6

  Parallel port             CN2       Floppy drive interface       CN7

  Serial port 2             CN3       VGA feature connector        CN8

  Serial port 1             CN4       CPU board connectors         CN9

  PS/2 mouse port           CN5       Riser slot                   SL1

                        USER CONFIGURABLE SETTINGS

                 Function                      Label         Position

     VGA IRQ9 disabled                         J1             Open

      VGA IRQ9 enabled                          J1            Closed

     On board video disabled                   J2             Open

      On board video enabled                    J2            Closed

     CMOS memory normal operation              J3           Pins 1 & 2
                                                              closed

      CMOS memory clear                         J3           Pins 2 & 3
                                                              closed

      Reset switch enabled                      J4            Closed

      Reset switch disabled                     J4             Open

      Parallel port unidirectional              J5           Pins 1 & 2
                                                              closed

      Parallel port bidirectional               J5           Pins 2 & 3
                                                              closed

     Factory configured - do not alter         J10            Open

     Monitor type select color                 J11           Closed

      Monitor type select monochrome            J11            Open

     Factory configured - do not alter         J29            Open

     Factory configured - do not alter         J30            Open

     Factory configured - do not alter         J31            Open

      VGAIOW select local                       J35          Pins 1 & 2
                                                              closed

      VGAIOW select local & ISA                 J35          Pins 2 & 3
                                                              closed

                           SIMM CONFIGURATION

     Size         Bank 0         Bank 1         Bank 2        Bank 3

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

     8MB        (1) 2M x 36       None           None          None

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

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

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

                       SIMM CONFIGURATION (CONT)

     Size         Bank 0         Bank 1         Bank 2        Bank 3

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

     16MB       (1) 4M x 36       None           None          None

     16MB       (1) 2M x 36   (1) 1M x 36    (1) 1M x 36       None

     16MB       (1) 2M x 36   (1) 2M x 36        None          None

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

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

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

     20MB       (1) 1M x 36   (1) 2M x 36    (1) 2M x 36       None

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

     24MB       (1) 4M x 36   (1) 1M x 36    (1) 1M x 36       None

     24MB       (1) 4M x 36   (1) 2M x 36        None          None

     24MB       (1) 2M x 36   (1) 2M x 36    (1) 2M x 36       None

     24MB       (1) 2M x 36   (1) 4M x 36        None          None

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

     32MB       (1) 8M x 36       None           None          None

     32MB       (1) 4M x 36   (1) 4M x 36        None          None

     32MB       (1) 2M x 36   (1) 2M x 36    (1) 2M x 36    (1) 2M x 36

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

     40MB       (1) 8M x 36   (1) 1M x 36    (1) 1M x 36       None

     40MB       (1) 8M x 36   (1) 2M x 36        None          None

     40MB       (1) 4M x 36   (1) 2M x 36    (1) 2M x 36    (1) 2M x 36

     40MB       (1) 2M x 36   (1) 4M x 36    (1) 4M x 36       None

     40MB       (1) 2M x 36   (1) 8M x 36        None          None

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

     48MB       (1) 8M x 36   (1) 2M x 36    (1) 2M x 36       None

     48MB       (1) 8M x 36   (1) 4M x 36        None          None

     48MB       (1) 4M x 36   (1) 4M x 36    (1) 4M x 36       None

     48MB       (1) 4M x 36   (1) 8M x 36        None          None

     56MB       (1) 8M x 36   (1) 2M x 36    (1) 2M x 36    (1) 2M x 36

     56MB       (1) 2M x 36   (1) 4M x 36    (1) 4M x 36    (1) 4M x 36

     64MB       (1) 8M x 36   (1) 4M x 36    (1) 4M x 36       None

     64MB       (1) 8M x 36   (1) 8M x 36        None          None

     64MB       (1) 4M x 36   (1) 4M x 36    (1) 4M x 36    (1) 4M x 36

                        VIDEO MEMORY CONFIGURATION

  Note: Board accepts 512KB/1MB of video memory. The configuration is
  unidentified.

    VIDEO MEMORY JUMPER CONFIGURATION

        Size                 J28

        512KB         Pins 1 & 2 closed

         1MB          Pins 2 & 3 closed

[Image]

                  CONNECTIONS

  Purpose                      Location

  CPU board connectors            CN9

     CACHE CONFIGURATION

     Size          Bank 0

     128KB      (4) 32K x 8

     256KB      (4) 64K x 8

                  CACHE JUMPER CONFIGURATION

        Size                 J103                 J104

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

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

               CPU SPEED SELECTION

  Speed     J109      J110      J111      J112

  33MHz    Closed     Open      Open      Open

  66iMHz   Closed     Open      Open      Open

                      CPU TYPE SELECTION

        Type                 J114                 J115

       80486SX         Pins 2 & 3 closed   Pins 2 & 3 closed

       80486DX         Pins 1 & 2 closed   Pins 1 & 2 closed

                        CPU SECOND SOCKET SELECTION

       Setting             J101              J102              J103

    Not installed        Pins 1 & 2       Pins 1 & 2        Pins 1 & 2
                          closed            closed            closed

       ODP486            Pins 1 & 2       Pins 1 & 2        Pins 1 & 2
                          closed            closed            closed

       80486DX           Pins 2 & 3       Pins 2 & 3        Pins 2 & 3
                          closed            closed            closed

      80486DX2           Pins 2 & 3       Pins 2 & 3        Pins 2 & 3
                          closed            closed            closed

[Image]

                  CONNECTIONS

  Purpose                      Location

  CPU board connectors            CN9

     CACHE CONFIGURATION

     Size          Bank 0

     128KB      (4) 32K x 8

     256KB      (4) 64K x 8

                  CACHE JUMPER CONFIGURATION

        Size                 J103                 J104

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

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

               CPU SPEED SELECTION

  Speed     J109      J110      J111      J112

  25MHz    Closed     Open      Open      Open

  50iMHz   Closed     Open      Open      Open

                        CPU SECOND SOCKET SELECTION

       Setting             J101              J102              J103

    Not installed        Pins 1 & 2       Pins 1 & 2        Pins 1 & 2
                          closed            closed            closed

       ODP486            Pins 1 & 2       Pins 1 & 2        Pins 1 & 2
                          closed            closed            closed

       80486DX           Pins 2 & 3       Pins 2 & 3        Pins 2 & 3
                          closed            closed            closed

      80486DX2           Pins 2 & 3       Pins 2 & 3        Pins 2 & 3
                          closed            closed            closed

