
DELL COMPUTER CORPORATION

System 486D

Processor            80486SX/80487SX/80486DX
Processor Speed      16/20/25/33
Chip Set             VLSI
Max. Onboard DRAM    64MB
Cache                None
BIOS                 AMI
Dimensions           329mm x 334mm
I/O Options          Bus mouse, floppy interface, IDE interface, parallel
                     port, serial ports (2), VGA port
NPU Options          None

[Image]

                                CONNECTIONS

  Purpose               Location     Purpose                   Location

  VGA port                 CN1       External battery            JBAT

  Parallel port            CN2       Cooling fan                 JFAN

  Serial port 2            CN3       VGA pass-through            JFEAT

  Serial port 1            CN4       Primary floppy drive        JFLOP
                                     interface

  Bus mouse port           CN5       IDE interface               JIDE

  Board ground             GND       Front panel status          JVIEW
  points                             LCD

  IDE interface LED       JLED

                        USER CONFIGURABLE SETTINGS

                 Function                     Jumper         Position

     Boot EEPROM select normal                CLRB            Open
      operation

      Boot EEPROM clear                        CLRB           Closed

     VGA interrupt request select none    JP5 pins 1 &        Open
                                                2

      VGA interrupt request select IRQ9    JP5 pins 1 &       Closed
                                                2

     Factory configured - do not alter    JP5 pins 3 &        Open
                                                4

     Monitor type select color            JP5 pins 5 &       Closed
                                                6

      Monitor type select monochrome       JP5 pins 5 &       Closed
                                                6

     Factory configured - do not alter    JP5 pins 7 &        Open
                                                8

     Password check disabled              JP5 pins 9 &        Open
                                                10

      Password check enabled               JP5 pins 9 &       Closed
                                                10

     Monitor type select standard VGA      JP5 pins 11        Open
                                               & 12

      Monitor type select Multifrequency    JP5 pins 11       Closed
      (MultiSync) VGA                          & 12

     IOCHRDY wait state(s) disabled        JP5 pins 17       Closed
                                               & 18

      IOCHRDY wait state(s) enabled         JP5 pins 17        Open
                                               & 18

     Boot source select normal (floppy     JP5 pins 19        Open
      or hard drive)                           & 20

      Boot source select Boot EEPROM on     JP5 pins 19       Closed
      AT bus                                   & 20

                            DRAM CONFIGURATION

     Size         Bank 0         Bank 1         Bank 2         Bank 3

     1MB         (1) 256K x       NONE           NONE           NONE
                    36

     2MB         (1) 256K x    (1) 256K x        NONE           NONE
                    36             36

     3MB         (1) 256K x    (1) 256K x     (1) 256K x        NONE
                    36             36             36

     4MB         (1) 256K x    (1) 256K x     (1) 256K x    (1) 256K x 36
                    36             36             36

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

     5MB        (1) 1M x 36    (1) 256K x        NONE           NONE
                                   36

     6MB        (1) 1M x 36    (1) 256K x     (1) 256K x        NONE
                                   36             36

     7MB        (1) 1M x 36    (1) 256K x     (1) 256K x    (1) 256K x 36
                                   36             36

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

     9MB        (1) 1M x 36   (1) 1M x 36     (1) 256K x        NONE
                                                  36

     10MB       (1) 1M x 36   (1) 1M x 36     (1) 256K x    (1) 256K x 36
                                                  36

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

     13MB       (1) 1M x 36   (1) 1M x 36    (1) 1M x 36    (1) 256K x 36

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

                        DRAM CONFIGURATION (CONT)

     Size         Bank 0         Bank 1         Bank 2         Bank 3

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

     17MB       (1) 4M x 36    (1) 256K x        NONE           NONE
                                   36

     18MB       (1) 4M x 36    (1) 256K x     (1) 256K x        NONE
                                   36             36

     19MB       (1) 4M x 36    (1) 256K x     (1) 256K x    (1) 256K x 36
                                   36             36

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

     21MB       (1) 4M x 36   (1) 1M x 36     (1) 256K x        NONE
                                                  36

     22MB       (1) 4M x 36   (1) 1M x 36     (1) 256K x    (1) 256K x 36
                                                  36

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

     25MB       (1) 4M x 36   (1) 1M x 36    (1) 1M x 36    (1) 256K x 36

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

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

     33MB       (1) 4M x 36   (1) 4M x 36     (1) 256K x        NONE
                                                  36

     34MB       (1) 4M x 36   (1) 4M x 36     (1) 256K x    (1) 256K x 36
                                                  36

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

     37MB       (1) 4M x 36   (1) 4M x 36    (1) 1M x 36    (1) 256K x 36

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

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

     49MB       (1) 4M x 36   (1) 4M x 36    (1) 4M x 36    (1) 256K x 36

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

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

             CPU SPEED CONFIGURATION

  Speed      JP1       JP2       JP3       JP4

  16MHz      Open     Open      Open     Closed

  20MHz      Open     Open     Closed     Open

  25MHz      Open    Closed     Open      Open

  33MHz     Closed    Open      Open      Open

                        IOCHRDY CONFIGURATION

              Setting                       JP5 pins 13 & 14

  Signal disabled to IDE drive(s)                Closed

  Signal enabled to IDE drive(s)                  Open

