GIGA-BYTE TECHNOLOGY CO., LTD.

GA-486US

Processor         80486SX/80486DX
Processor Speed   16/20/25/33/50MHz
Chip Set          UMC
Max. Onboard DRAM 32MB
SRAM Cache        64/128/256KB
BIOS              AMI
Dimensions        330mm x 218mm
I/O Options       32-bit local bus card slots (2)
NPU Options       4167

[Image]

                                CONNECTIONS

  Purpose                  Location    Purpose                  Location

  Power LED & Keylock         J1       External battery           J17

  Reset switch                J2       32-bit local bus         LB1 & LB2
                                       slots

  Speaker                     J3                                  LB2

  Turbo LED                   J5

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

  »   External cache enabled                   J4            pins 1 & 2
                                                              closed

      External cache disabled                  J4            pins 2 & 3
                                                              closed

      CPU type select 80486DX                  J8            pins 1 & 2
                                                              closed

      CPU type select 80486SX                  J8            pins 2 & 3
                                                              closed

  »   CPU speed select iOSC/1                  J13             Open

      CPU speed select iOSC/2                  J13            Closed

  »   Monitor type select color                J16            Closed

      Monitor type select monochrome           J16             Open

  »   CMOS memory normal operation             J18            Closed

      CMOS memory clear                        J18             Open

  Note:If J13 is closed, you must set the Bus speed select to CLKIN/5 in
  the advanced chipset setup.

              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    (3) 16K x 4

     128KB      (4) 32K x 8        NONE       (3) 16K x 4

     256KB      (4) 32K x 8    (4) 32K x 8    (3) 16K x 4

                            CACHE CONFIGURATION

      Size               J10               J11                 J12

      64KB            pins 1 & 2        pins 1 & 2      pins 1 & 2 closed
                       closed             closed

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

      256KB           pins 2 & 3        pins 2 & 3      pins 2 & 3 closed
                       closed             closed