
DD & TT ENTERPRISE USA COMPANY

DT ESCORT SYSTEM BOARD B

Processor             80486SX/80486DX/ODP486SX/80486DX2
Processor Speed       16/20/25/33/50(internal)/50/66(internal)MHz
Chip Set              OPTI
Max. Onboard DRAM     32MB
Cache                 64KB/256KB
BIOS                  AMI
Dimensions            330mm x 218mm
I/O Options           Floppy drive interface, IDE interface parallel port,

                      Proprietary EISA riser card slot, PS/2 mouse port,

                      Serial port (2), VGA port, video feature connector
NPU Options           None

[Image]

                                CONNECTIONS

  Purpose                Location     Purpose                  Location

  PS/2 mouse port           J2        Reset switch               J12A

  Serial port (COM 1)       J3        Turbo switch               J12B

  Serial port (COM 2)       J4        Turbo LED                  J12C

  Parallel port             J5        IDE interface LED          J12D

  VGA port                  J6        Not used                   J12E

  Floppy drive              J9        Speaker                    J13A
  interface

  Video feature            J10        Power LED & keylock        J13B
  connector

  IDE interface            J11        Proprietary EISA            S1
                                      riser card slot

                        USER CONFIGURABLE SETTINGS

             Function                  Jumper/Switch         Position

     Floppy drive disabled                  E1              Pins 1 & 3
                                                              closed

      Floppy drive enabled                   E1              Pins 3 & 5
                                                              closed

      Floppy drive address select            E1              Pins 7 & 9
      3FO-3F7                                                 closed

      Floppy drive address select            E1             Pins 9 & 11
      370-377                                                 closed

     IDE interface disabled                 E1              Pins 2 & 4
                                                              closed

      IDE interface enabled                  E1              Pins 4 & 6
                                                              closed

      IDE interface address                  E1             Pins 8 & 10
      select 3FO-3F7, 1FO-1F7                                 closed

      IDE interface address                  E1             Pins 10 & 12
      select 370-377, 170-177                                 closed

     Onboard video enabled                  E2           Pins 1 & 2, 3 &
                                                          4, 5 & 6 closed

      Onboard video disabled                 E2           Pins 1 & 2, 3 &
                                                           4, 5 & 6 open

     BIOS device select 1MB                 E6              Pins 1 & 2
                                                              closed

      BIOS device select 2MB                 E6              Pins 3 & 5
                                                              closed

      BIOS device select read                E6           Pins 2 & 4, 7 &
      only                                                   9, 8 & 10
                                                              closed

      BIOS device select                     E6           Pins 4 & 6, 9 &
      read/write                                            11, 10 & 12

     Chipset mode select 2x for             E7              Pins 3 & 5
      40MHz or less                                           closed

      Chipset mode select 1x for             E7              Pins 1 & 3
      true 50MHz only                                         closed

      Chipset mode RDY1 set for              E7              Pins 4 & 6
      1X mode                                                 closed

      Chipset mode RDY2 set for              E7              Pins 2 & 4
      2X mode                                                 closed

     Chipset mode burst rate                E8             Pins 23 & 24
      select 3-2-2-2                                          closed

      Chipset mode burst rate                E8             Pins 23 & 24
      select 2-1-1-1                                           open

     Chipset mode write states              E8             Pins 25 & 26
      select 0 wait state                                     closed

      Chipset mode write states              E8             Pins 25 & 26
      select 1 wait state                                      open

     Factory configured - do not            E9             Pins 39 & 40
      alter                                                   closed

     PS/2 mouse enable at IRQ12            E10               Closed

      PS/2 mouse disable                    E10                Open

     Factory configured do not             E11               Unknown
      alter

     CPU clock select mode 2X              E12              Pins 2 & 3
                                                              closed

      CPU clock select mode 1 x             E12              Pins 1 & 2
      for 486DX 50MHz                                         closed

     Factory configured - do not           E15              Pins 1 & 2
      alter                                                   closed

  Note: If there is no monochrome Hercules card present then the system
  will automatically assume that address 378h is LPT1 and address 278h is
  LPT2 pins designated should be in the closed position.

              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) 4M x 9         None

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

      17MB        (4) 256K x 9    (4) 4M x 9

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

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

                    SRAM CONFIGURATION

     Size          Cache         Location         TAG

     64KB        (8) 8K x 8     Bank 0 & 1    (1) 8K x 4

     256KB      (8) 32K x 8     Bank 0 & 1    (1) 32K x 4

                         SRAM JUMPER CONFIGURATION

          E9                     64KB                     256KB

     Pins 1, 3, 5         Pins 1 & 3 closed         Pins 3 & 5 closed

     Pins 2, 4, 6         Pins 2 & 4 closed         Pins 2 & 4 closed

    Pins 7, 9, 11         Pins 7 & 9 closed         Pins 9 & 11 closed

    Pins 8, 10, 12               Open               Pins 8 & 10 closed

   Pins 13, 15, 17       Pins 15 & 17 closed       Pins 15 & 17 closed

   Pins 14, 16, 18       Pins 14 & 16 closed       Pins 14 & 16 closed

   Pins 19, 21, 23       Pins 21 & 23 closed       Pins 21 & 23 closed

   Pins 20, 22, 24               Open              Pins 20 & 22 closed

   Pins 26, 28, 30       Pins 26 & 28 closed       Pins 26 & 28 closed

   Pins 31, 33, 35       Pins 33 & 35 closed       Pins 33 & 35 closed

   Pins 32, 34, 36       Pins 34 & 36 closed       Pins 34 & 36 closed

     Pins 37 & 38                Open                     Closed

  Note: For non-cache configuration pins 25, 26, & 27 should be in the
  closed position.

                        NON CACHE CONFIGURATION E16

  Pins 1-3-5  Pins 2-4-6      Pins       8 & 10,     Pins 13 &   15 & 16,
                             7-9-11      11 & 12        14       17 & 18

    3 & 5        2 & 4        7 & 9      Closed       Closed      Open
   closed       closed       closed

                          CPU TYPE CONFIGURATION

      Jumper             80486DX/80486DX2           80386SX/80486SLC

  E8/pins 1, 3, 5       Pins 1 & 3 closed           Pins 3 & 5 closed

  E8/pins 2, 4, 6       Pins 2 & 4 closed           Pins 4 & 6 closed

  E8/pins 7, 9, 11      Pins 7 & 9 closed          Pins 9 & 11 closed

   E8/pins 8, 10,       Pins 8 & 10 closed         Pins 10 & 12 closed
        12

  E8/pins 13 & 14             Closed                      Open

  E8/pins 15 & 16              Open                      Closed

  E8/pins 17 & 18             Closed                      Open

  E8/pins 19 & 20             Closed                      Open

  E8/pins 21 & 22              Open                      Closed

  E13/pins 1 & 2,    Pins 1 & 2, 3 & 4, 5 & 6       Pins 2 & 3 closed
   3 & 4, 5 & 6               closed

  Note: settings for the 80386SX and 80486SLC are factory configured and
  should not be altered.

                          CPU SPEED CONFIGURATION

  Speed       U51         U52        Pins 1    Pins 3    Pins 5    Pins 7
                                      & 2       & 4       & 6       & 8

  16MHz    Installed     Empty      Closed     Open     Closed      N/A

  16MHz      Empty      Installed   Closed     Open     Closed    Closed

  20MHz    Installed     Empty      Closed     Open      Open       N/A

  20MHz      Empty      Installed    Open      Open     Closed    Closed

  25MHz    Installed     Empty       Open     Closed    Closed      N/A

  25MHz      Empty      Installed   Closed    Closed     Open     Closed

  33MHz    Installed     Empty       Open     Closed     Open       N/A

  33MHz      Empty      Installed    Open     Closed     Open     Closed

  40MHz    Installed     Empty       Open      Open     Closed      N/A

  40MHz      Empty      Installed   Closed     Open      Open     Closed

  50MHz    Installed     Empty       Open     Closed    Closed      N/A

  50MHz      Empty      Installed   Closed    Closed     Open     Closed

                     SERIAL PORT A (J3) CONFIGURATION

          COM              I/O Address           E4              E5

           COM1               3F8h         Pins 3 & 5, 2   Pins 3 & 5, 2
                                             & 4, 7 & 8      & 4, 7 & 8

            COM3               3E8h         Pins 1 & 3, 4   Pins 1 & 3, 4
                                             & 6, 7 & 8      & 6, 7 & 8

            COM4               2E8h         Pins 3 & 5, 4   Pins 3 & 5, 4
                                             & 6, 7 & 8          & 6

          Disabled             N/A          Pins 1 & 3, 2   Pins 1 & 3, 2
                                                 & 4             & 4

  Note: Pins designated should be in the closed position.

                     SERIAL PORT B (J4) CONFIGURATION

          COM              I/O Address           E4              E5

           COM2               2F8h         Pins 3 & 5, 2   Pins 3 & 5, 2
                                             & 4, 7 & 8      & 4, 7 & 8

            COM3               3E8h         Pins 1 & 3, 4   Pins 1 & 3, 4
                                             & 6, 7 & 8      & 6, 7 & 8

            COM4               2E8h         Pins 3 & 5, 4   Pins 3 & 5, 4
                                             & 6, 7 & 8          & 6

          Disabled             N/A          Pins 1 & 3, 2   Pins 1 & 3, 2
                                                 & 4             & 4

  Note: Pins designated should be in the closed position.

                     PARALLEL PORT (J5) CONFIGURATION

          COM                IRQ          I/O Address            E3

           LPT1             IRQ7            3BCh           Pins 3 & 5, 4
                                                             & 6, 7 & 8

            LPT1             IRQ5            3BCh           Pins 3 & 5, 4
                                                            & 6, 9 & 10

            LPT2             IRQ7            378h           Pins 3 & 5, 2
                                                             & 6, 7 & 8

            LPT2             IRQ5            378h           Pins 3 & 5, 2
                                                            & 6, 9 & 10

            LPT3             IRQ7            278h           Pins 1 & 3, 4
                                                             & 6, 7 & 8

            LPT3             IRQ5            278h           Pins 1 & 3, 4
                                                            & 6, 9 & 10

          Disabled           N/A              N/A           Pins 1 & 3, 2
                                                                & 4

  Note: Pins designated should be in the closed position.

               VIDEO MEMORY CONFIGURATION

       Size               Bank 0            Bank 1

       512KB            (4) 44256            NONE

      1024KB            (4) 44256          (4) 44256

  Note: Bank 0 is permanently soldered onto the board.

