
COMPAQ COMPUTER CORPORATION

PRESARIO 400 SERIES

Processor       80486SX/80487SX/80486DX/ODP486SX/80486DX2
Processor Speed 25/33/50(internal)/66(internal)MHz
Chip Set        Compaq
Max. Onboard    16MB
DRAM
Cache           None
BIOS            AMI
Dimensions      330mm x 218mm
I/O Options     Riser card, floppy drive interface, game port, IDE
                interface, parallel port, PS/2 mouse port, serial port
NPU Options     None

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  PS/2 mouse port             CN1      Power LED & keylock         J2

  Serial port                 CN2      Floppy drive interface      J3

  Parallel port               CN3      Speaker                     J13

  Game port                   CN4      External battery            J16

  Modem ports                 CN5      Riser Card                  SL1

  IDE interface               J1

                        USER CONFIGURABLE SETTINGS

                Function                    Jumper           Position

     CPU type select PGA                     P2            pins 2 & 3
                                                              closed

      CPU type select PQFP                    P2            pins 1 & 2
                                                              closed

     CMOS memory normal operation            P6               Open

      CMOS memory clear                       P6              Closed

     Modem ROM select internal               P7            pins 1 & 2
                                                              closed

      Modem ROM select external               P7            pins 2 & 3
                                                              closed

                DRAM CONFIGURATION

      Size            Bank 0           Bank 1

       1MB        (1) 256K x 36         NONE

       2MB        (1) 256K x 36    (1) 256K x 36

       2MB        (1) 512K x 36         NONE

       3MB        (1) 256K x 36    (1) 512K x 36

       4MB        (1) 512K x 36    (1) 512K x 36

       4MB         (1) 1M x 36          NONE

       5MB        (1) 256K x 36     (1) 1M x 36

       6MB        (1) 512K x 36     (1) 1M x 36

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

       8MB         (1) 2M x 36          NONE

       9MB        (1) 256K x 36     (1) 2M x 36

      10MB        (1) 512K x 36     (1) 2M x 36

      12MB         (1) 1M x 36      (1) 2M x 36

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

                          CPU TYPE CONFIGURATION

       Type                P3                P4                 P5

  80486SX (PQFP)       pins 1 & 2         pins 1 & 2        pins 1 & 2
                         closed            closed             closed

   80486SX (PGA)       pins 2 & 3         pins 2 & 3        pins 3 & 4
                         closed            closed             closed

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

     ODP486SX          pins 1 & 2         pins 1 & 2        pins 2 & 3
                         closed            closed             closed

      80486DX          pins 1 & 2         pins 1 & 2        pins 1 & 2
                         closed            closed             closed

     80486DX2          pins 1 & 2         pins 1 & 2        pins 1 & 2
                         closed            closed             closed

         CPU SPEED CONFIGURATION

        Speed                 P1

        25MHz         pins 1 & 2 closed

        33MHz         pins 2 & 3 closed

       50iMHz         pins 1 & 2 closed

       66iMHz         pins 2 & 3 closed

   MISCELLANEOUS TECHNICAL NOTE

  The purpose of CN6 is unknown.

