COMPAQ COMPUTER CORPORATION

DESKPRO 286 (12MHz)

Processor         80286
Processor Speed   12MHz
Chip Set          ETEQ
Max. Onboard DRAM 2.125MB
Cache             None
BIOS              Compaq
Dimensions        330mm x 218mm
I/O Options       None
NPU Options       80287

[Image]

                                CONNECTIONS

  Purpose                 Location     Purpose                 Location

  Fixed drive power         J109       Proprietary               J116
                                       keyboard connector

  Fixed drive/Tape          J110       Main power                J117
  backup power

  Floppy drive power        J111       External battery          J118

  Floppy drive power        J112       Keylock                   J119

  Monitor power             J113       Onboard power LED         LED1

  Speaker                   J115

                                       USER CONFIGURABLE SETTINGS

                           Function                               Jumper/Switch          Position

  »   Oscillator type select single package                            E3                 Closed

      Oscillator type select dual package                              E3                  Open

  »   Memory operation generation select discrete gate                 E4           pins 1 & 2 closed

      Memory operation generation select CBC internal                  E4           pins 2 & 3 closed

  »   Auto slowdown disabled in software                               E5           pins 1 & 2 closed

      Auto slowdown enabled in software                                E5           pins 2 & 3 closed

  »   CPU speed select switchable at keyboard                         SW1/6                Off

      CPU speed select forced slow                                    SW1/6                 On

  »   Factory configured - do not alter                               SW1/7                Off

  »   Monitor type select color                                       SW1/8                 On

      Monitor type select monochrome                                  SW1/8                Off

      Notes: Settings for E3, E4, and E5 are accomplished by cutting the conductors on the bottom of
      the board and re-soldering the indicated locations.

      WARNING: Modifying E3, E4, or E5 will void the manufacturers warranty!

                            DRAM CONFIGURATION

    Size      Bank 0    P-0      Bank 1     Bank 2    Bank 3     Bank 4

   256KB       (4)       (2)      (18)       NONE      NONE       NONE
              4464      4164      4164

   512KB       (4)       (2)      (18)       (18)       (18)      NONE
              4464      4164      4164       4164      4164

   640KB       (4)       (2)      (18)       (18)       (18)    (18) 4164
              4464      4164      4164       4164      4164

   640KB       (4)       (2)      (18)       NONE      NONE       NONE
              4464      4164     41256

  1.125MB      (4)       (2)      (18)       (18)      NONE       NONE
              4464      4164     41256      41256

  1.625MB      (4)       (2)      (18)       (18)       (18)      NONE
              4464      4164     41256      41256      41256

  2.125MB      (4)       (2)      (18)       (18)       (18)       (18)
              4464      4164     41256      41256      41256      41256

                         DRAM SWITCH CONFIGURATION

     Size        SW1/1       SW1/2       SW1/3       SW1/4        SW1/5

   Disabled       N/A          On          On         N/A          N/A

    256KB         On           On         Off         Off          Off

    512KB         On          Off          On         Off          Off

    640KB         On          Off         Off         Off          Off

    640KB         Off         Off         Off          On          On

   1.125MB        Off         Off         Off          On          Off

   1.625MB        Off         Off         Off         Off          On

   2.125MB        Off         Off         Off         Off          Off

  Notes: Closing both SW1/switch 2 and SW1/switch 3, disables banks 0 & 1
  and any onboard ROM.

                         ROM JUMPER CONFIGURATION

      ROM type            Size           BIOS ROM/E1       ROM set 2/E2

       Static            8K x 8       1 & 2, 4 & 5, 7 &   1 & 2, 4 & 5, 7
                                              8                 & 8

       Static           16K x 8       2 & 3, 4 & 5, 7 &   2 & 3, 4 & 5, 7
                                              8                 & 8

       Static           32K x 8       2 & 3, 4 & 5, 7 &   2 & 3, 5 & 6, 7
                                              8                 & 8

      Dynamic            8K x 8       1 & 2, 4 & 5, 8 &   1 & 2, 4 & 5, 8
                                              9                 & 9

      Dynamic           16K x 8       2 & 3, 4 & 5, 8 &   2 & 3, 4 & 5, 8
                                              9                 & 9

      Dynamic           32K x 8       2 & 3, 5 & 6, 8 &   2 & 3, 5 & 6, 8
                                              9                 & 9

  Notes: Settings are accomplished by cutting the conductors on the
  bottom of the board and re-soldering the indicated locations. Pins
  designated should be in the closed position.

  WARNING: Modifying the factory configurations will void the
  manufacturers warranty!