UNIDENTIFIED

80486SX/DX MOTHERBOARD

Processor         80486SX/80487SX/80486DX
Processor Speed   16/20/25/33MHz
Chip Set          Acer
Max. Onboard DRAM 32MB
SRAM Cache        None
BIOS              AMI/AWARD
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

                        I/O BUS SPEED CONFIGURATION

      Jumper            OSC1/5            OSC1/6             OSC1/8

       JP3            pins 2 & 3         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

       JP6            pins 1 & 2         pins 2 & 3         pins 1 & 2
                        closed            closed             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 JUMPER CONFIGURATION

         CPU                 JP4                  JP5

       80486SX               open          pins 1 & 2 closed

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

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