
ADVANCED COMPUTER TECHNOLOGY, LTD.

T486SX-20/T486DX-25/T486DX-33

Processor         80486SX/80487SX/80486DX
Processor Speed   20/25/33MHz
Chip Set          ACT
Max. Onboard DRAM 32MB
Cache             None
BIOS              AMI
Dimensions        330mm x 218mm
I/O Options       None
NPU Options       None

[Image]

                                CONNECTIONS

  Purpose                   Location    Purpose                  Location

  Power LED & Keylock         JP22      Speaker                   JP28

  Reset switch                JP24      Turbo switch              JP30

  External battery            JP25      Turbo LED                 JP31

                        USER CONFIGURABLE SETTINGS

                 Function                     Jumper         Position

     RAM speed select fast (40 to 70ns)    JP4 & JP5        pins 1 & 2
                                                              closed

      RAM speed select slow (80 to          JP4 & JP5        pins 2 & 3
      120ns)                                                  closed

     Video BIOS cacheable                     JP7           pins 1 & 2
                                                              closed

      Video BIOS non-cacheable                 JP7           pins 2 & 3
                                                              closed

     Factory configured - do not alter        JP11             N/A

     Monitor type select color                JP23          pins 2 & 3
                                                              closed

      Monitor type select monochrome           JP23          pins 1 & 2
                                                              closed

     Battery select internal                  JP26          pins 1 & 2
                                                              closed

      Battery select external                  JP26          pins 2 & 3
                                                              closed

     Power good signal detect from            JP27          pins 1 & 2
      power supply                                            closed

      Power good signal detect from            JP27          pins 2 & 3
      board                                                   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

                         DRAM JUMPER CONFIGURATION

      Size              JP8                JP9                JP10

      1MB            pins 1 & 2         pins 1 & 2      pins 1 & 2 closed
                      closed              closed

      2MB            pins 1 & 2         pins 1 & 2      pins 2 & 3 closed
                      closed              closed

      4MB            pins 1 & 2         pins 2 & 3      pins 1 & 2 closed
                      closed              closed

      8MB            pins 1 & 2         pins 2 & 3      pins 2 & 3 closed
                      closed              closed

      16MB           pins 2 & 3         pins 2 & 3      pins 1 & 2 closed
                      closed              closed

      32MB           pins 2 & 3         pins 2 & 3      pins 2 & 3 closed
                      closed              closed

                          CPU TYPE CONFIGURATION

      Type           JP2            JP3           JP6            JP12

    80486SX -     pins 1 & 2     pins 1 & 2    pins 1 & 2     pins 1 & 2
     20MHz          closed        closed         closed         closed

    80486SX -     pins 2 & 3     pins 1 & 2    pins 1 & 2     pins 1 & 2
     33MHz          closed        closed         closed         closed

    80487SX -     pins 1 & 2     pins 1 & 2    pins 2 & 3     pins 2 & 3
     20MHz          closed        closed         closed         closed

    80486DX -     pins 2 & 3     pins 2 & 3    pins 2 & 3     pins 2 & 3
   25/33 MHz        closed        closed         closed         closed

