
AUSTIN COMPUTER SYSTEMS

486U

Processor        80486SX/80487SX/80486DX/80486DX2
Processor Speed  20/25/33/50(internal)/50/66(internal)MHz
Chip Set         OPTI
Max. Onboard     32MB
DRAM
Cache            64/256KB
BIOS             Mylex
Dimensions       330mm x 218mm
I/O Options      Floppy drive interface, IDE interface, parallel port,
                 serial ports (2)
NPU Options      4167

[Image]

                                CONNECTIONS

  Purpose                   Location    Purpose                  Location

  Parallel port                J1       Turbo LED                  JP3

  Serial port COM 2            J2       Reset switch               JP4

  Serial port COM 1            J3       Speaker                    JP5

  Floppy controller            J4       IDE interface LED          JP6

  IDE interface                J5       External battery          JP22

  Power LED & keylock         JP2

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Monitor type select monochrome           JP1             open

      Monitor type select color                JP1            closed

     Parallel port IRQ select IRQ7           JP19           pins 2 & 3
                                                              closed

      Parallel port IRQ select IRQ5           JP19           pins 1 & 2
                                                              closed

     CMOS memory normal operation            JP21           pins 2 & 3
                                                              closed

      CMOS memory clear                       JP21           pins 1 & 2
                                                              closed

              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) 1M x 9     (4) 256K x 9

      8MB         (4) 1M x 9      (4) 1M x 9

      16MB        (4) 4M x 9         NONE

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

                    CACHE CONFIGURATION

     Size          Bank 0        TAG (U1)      TAG (U2)

     64KB        (8) 8K x 8    (1) 64K x 1    (1) 8K x 8

     256KB      (8) 32K x 8    (1) 64K x 1    (1) 32K x 8

           CACHE JUMPER CONFIGURATION

   Size      JP7      JP11      JP12      JP13

   64KB     Open      Open      Open      Open

  256KB    Closed    Closed     Open     Closed

                          CPU TYPE CONFIGURATION

     Type              JP8                 JP9                 JP10

    80486SX            Open          pins 2 & 3 closed         Open

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

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

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

                     CPU SPEED CONFIGURATION

   Speed      JP14       JP15       JP16       JP17       JP18

   20MHz      2 & 3      1 & 2      2 & 3      1 & 2      Open

   25MHz      2 & 3      2 & 3      1 & 2      2 & 3      Open

   33MHz      2 & 3      1 & 2      1 & 2      2 & 3      Open

   50MHz      1 & 2      2 & 3      1 & 2      2 & 3     Closed

  50iMHz      2 & 3      2 & 3      1 & 2      2 & 3      Open

  66iMHz      2 & 3      1 & 2      1 & 2      2 & 3      Open

  Note: Pins designated should be in the closed position.

                        ON BOARD I/O CONFIGURATION

                    Setting                                JP20

  Serial port 1, serial port 2, parallel port,       pins 1 & 2 closed
         floppy drive interface enabled

  Serial port 1, serial port 2, parallel port,       pins 2 & 3 closed
        floppy drive interface disabled

