
GIGA-BYTE TECHNOLOGY CO., LTD.

GA-486TA

Processor        80486SX/80486DX/80486DX2/Pentium Overdrive
Processor Speed  25/33/40(internal)/50(internal)/50/66(internal)MHz
Chip Set         OPTI
Max. Onboard DRAM128MB
Cache            64/128/256/512KB
BIOS             AMI
Dimensions       330mm x 218mm
I/O Options      32-bit VESA local bus slots (2)
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                  Location     Purpose                 Location

  Power LED & keylock         J1        Turbo switch               J4

  Reset switch                J2        Turbo LED                  J5

  Speaker                     J3        32-bit VESA Local      SL1 & SL2
                                        bus slots

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     CPU type select 80486DX/P24T             J6            pins 1 & 2
                                                              closed

      CPU type select 80486SX                  J6            pins 2 & 3
                                                              closed

     Monitor type select color                J14            Closed

      Monitor type select monochrome           J14             Open

     CMOS memory normal operation             J17             Open

      CMOS memory clear                        J17            Closed

     Factory configured - do not alter        J18           pins 2 & 3
                                                              closed

     Factory configured - do not alter        J23           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

      64MB        (4) 16M x 9        NONE

     128MB        (4) 16M x 9    (4) 16M 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) 32K x 8

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

     512KB       (1) 128K x 8        NONE        (1) 32K x 8

                        CACHE JUMPER CONFIGURATION

    Size           J8             J9            J10             J11

    64KB          Open           Open           Open            N/A

    128KB         Open          Closed          Open         pins 1 & 2
                                                               closed

    256KB         Open          Closed         Closed        pins 2 & 3
                                                               closed

    512KB        Closed         Closed         Closed        pins 1 & 2
                                                               closed

                          CPU SPEED CONFIGURATION

      Speed              JC0                JC1                JC2

      25MHz           pins 2 & 3         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

      33MHz           pins 2 & 3         pins 2 & 3         pins 2 & 3
                        closed            closed             closed

      40MHz           pins 2 & 3         pins 2 & 3         pins 1 & 2
                        closed            closed             closed

      50iMHz          pins 2 & 3         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

      50MHz           pins 1 & 2         pins 1 & 2         pins 2 & 3
                        closed            closed             closed

      66iMHz          pins 2 & 3         pins 2 & 3         pins 2 & 3
                        closed            closed             closed

              VESA WAIT STATE/BUS SPEEDCONFIGURATION

    CPU speed      Wait states          J31              J32

      33MHz      0 wait states         Open            Open

     > 33MHz       1 wait state        Closed          Closed

