TEXAS MICROSYSTEMS, INC.

D486 (REL. 2)

Processor           80486DX/80486DX2/80486DX4
Processor Speed     33/50/66(internal)/100(internal)MHz
Chip Set            Unidentified
Video Chip Set      None
Maximum Onboard     128MB
Memory
Maximum Video       None
Memory
Cache               64/128/256KB
BIOS                Unidentified
Dimensions          Unidentified
I/O Options         Floppy drive interface, IDE interface, parallel port,
                    serial ports (2)
NPU Options         None

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  IDE interface               CN1      Parallel port               CN5

  Floppy drive interface      CN2      AT keyboard connector       CN6

  Serial port 2               CN3      External battery            JP9

  Serial port 1               CN4      IDE interface LED          JP10

                        USER CONFIGURABLE SETTINGS

                Function                     Label           Position

  »   Battery type select internal            JP9           Pins 1 & 2
                                                              closed

      Battery type select external            JP9             Closed

  »   Watchdog timer disabled                 JP11          Pins 2 & 3
                                                              closed

      Watchdog timer enabled                  JP11          Pins 1 & 2
                                                              closed

  »   Monitor type select color              SW1/1              On

      Monitor type select monochrome         SW1/1             Off

  »   Flash BIOS enabled                     SW1/2             Off

      Flash BIOS disabled                    SW1/2              On

  »   CMOS memory normal operation           SW1/3             Off

      CMOS memory clear                      SW1/3              On

  »   I/O address select 270H                SW1/4             Off

      I/O address select 370H                SW1/4              On

             DRAM CONFIGURATION

     Size          Bank 0        Bank 1

      8MB        (2) 1M x 36      None

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

     24MB        (2) 2M x 36   (2) 1M x 36

     32MB        (2) 4M x 36      None

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

     48MB        (2) 4M x 36   (2) 2M x 36

     64MB        (2) 8M x 36      None

     64MB        (2) 4M x 36   (2) 4M x 36

     96MB        (2) 8M x 36   (2) 4M x 36

     128MB       (2) 8M x 36   (2) 8M x 36

  Note: Board also accepts x 32 SIMMs.

                        CACHE CONFIGURATION

  Note: The chip sizes and location of the cache is unidentified.

                        CACHE JUMPER CONFIGURATION

    Size           JP5            JP6            JP7             JP8

    64KB        Pins 1 & 2     Pins 1 & 2     Pins 1 & 2        Open
                 closed          closed         closed

    128KB       Pins 2 & 3     Pins 1 & 2     Pins 2 & 3      Pins 1 & 2
                 closed          closed         closed         closed

    256KB       Pins 2 & 3     Pins 2 & 3     Pins 1 & 2      Pins 2 & 3
                 closed          closed         closed         closed

           CPU SPEED SELECTION

        Speed                JP4

        33MHz         Pins 1 & 2 closed

                            CPU TYPE SELECTION

      Type           JP1            JP2           JP3            JP14

    80486DX       Pins 1 & 2     Pins 2 & 3    Pins 1 & 2     Pins 2 & 3
                    closed        closed         closed         closed

    80486DX2      Pins 1 & 2     Pins 2 & 3    Pins 1 & 2     Pins 2 & 3
                    closed        closed         closed         closed

    80486DX4      Pins 1 & 2     Pins 2 & 3    Pins 1 & 2     Pins 1 & 2
                    closed        closed         closed         closed

  CPU MULTIPLIER SELECTION (80486DX4 ONLY)

      Multiplier               JP13

          2x             Pins 2 & 3 closed

          3x             Pins 1 & 2 closed

                         WATCHDOG TIMER SELECTION

                 Timer                                 JP12

  »                 150ms                        Pins 2 & 3 closed

                    600ms                              Open

                 1.2 seconds                     Pins 1 & 2 closed