
ABIT COMPUTER CORPORATION

486SX-AR4

Processor         80486SX/80487SX/80486DX
Processor Speed   20/25/33MHz
Chip Set          Acer
Max. Onboard DRAM 32MB
Cache             None
BIOS              AMI
Dimensions        230mm x 220mm
I/O Options       None
NPU Options       None

[Image]

                                CONNECTIONS

  Purpose               Location       Purpose                Location

  External battery         J4          Turbo LED           J21 pins 1 & 2

  Reset switch             J19         Turbo switch        J21 pins 4 & 5

  Speaker                  J20         Power LED &              J22
                                       keylock

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Monitor type select color                JP1           pins 2 & 3
                                                              closed

      Monitor type select monochrome           JP1           pins 1 & 2
                                                              closed

     Real time clock select MC146818          JP2             Open

      Real time clock select DS1287            JP2            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

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

      16MB        (4) 4M x 9         NONE

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

                    CPU TYPE CONFIGURATION

        Type                 JP4                  JP5

       80486SX         pins 1 & 2 closed   pins 2 & 3 closed

       80487SX               Open          pins 1 & 2 closed

       80486DX         pins 2 & 3 closed   pins 2 & 3 closed

                 I/O BUS SPEED CONFIGURATION

        Speed                JP3                  JP6

       CLK2/5          pins 2 & 3 closed   pins 1 & 2 closed

       CLK2/6          pins 1 & 2 closed   pins 2 & 3 closed

       CLK2/8          pins 1 & 2 closed   pins 1 & 2 closed

