
GIGA-BYTE TECHNOLOGY, INC.

GA-486UM

Processor              80486SX/80487SX/80486DX/ODP486SX/80486DX2
Processor Speed        16/20/25/33/50(internal)/50/66(internal)MHz
Chip Set               OPTI
Max. Onboard DRAM      32MB
Cache                  64/128/256KB
BIOS                   AMI
Dimensions             220mm x 240mm
I/O Options            None
NPU Options            None

[Image]

                                CONNECTIONS

  Purpose                   Location    Purpose                  Location

  External battery             J3       Turbo switch               J10

  Speaker                      J8       Turbo LED                  J11

  Power LED & keylock          J9       Reset                      J12

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Monitor type select color                J6             Closed

      Monitor type select monochrome           J6              Open

     CMOS memory normal operation             J13           pins 1 & 2
                                                              closed

      CMOS memory clear                        J13           pins 2 & 3
                                                              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

                    CACHE CONFIGURATION

     Size          Bank 0         Bank 1          TAG

     64KB        (4) 8K x 8     (4) 8K x 8    (1) 8K x 8

     128KB      (4) 32K x 8        NONE       (1) 8K x 8

     256KB      (4) 32K x 8    (4) 32K x 8    (1) 32K x 8

                        CACHE JUMPER CONFIGURATION

     Size           W1              W2             W7             W9

     64KB        pins 1 & 2        Open           Open           Open
                  closed

    128KB        pins 2 & 3     pins 1 & 2        Open          Closed
                  closed          closed

    256KB        pins 1 & 2     pins 2 & 3       Closed         Closed
                  closed          closed

                          CPU TYPE CONFIGURATION

        Type             OSC Speed           W10               W11

     80486SX-16            16MHz             Open           pins 2 & 3
                                                              closed

     80486SX-20            20MHz             Open           pins 2 & 3
                                                              closed

     80486SX-20            40MHz            Closed          pins 2 & 3
                                                              closed

     80486SX-25            25MHz             Open           pins 2 & 3
                                                              closed

     80487SX-25            25MHz             Open           pins 1 & 2
                                                              closed

     80486DX-25            25MHz             Open           pins 1 & 2
                                                              closed

     80486DX-33            33MHz             Open           pins 1 & 2
                                                              closed

     80486DX-50            50MHz             Open           pins 1 & 2
                                                              closed

     80486DX2-50           25MHz             Open           pins 1 & 2
                                                              closed

     80486DX2-66           33MHz             Open           pins 1 & 2
                                                              closed

