
TANDY/RADIO SHACK

4825 SX

Processor           80486SX/80487SX/80486DX/80486DX2
Processor Speed     25/33/50(internal)/66(internal)MHz
Chip Set            Unidentified
Video Chip Set      Unidentified
Maximum Onboard     32MB
Memory
Maximum Video       1MB
Memory
Cache               None
BIOS                Unidentified
Dimensions          394mm x 381mm
I/O Options         Floppy drive interface, IDE interface, parallel port,
                    PS/2 mouse port, serial ports (2), VGA feature
                    connector, VGA port, riser slot
NPU Options         None

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  VGA port                    CN1      IDE interface               CN8

  PS/2 mouse port             CN2      External battery            J1

  Parallel port               CN3      Speaker                     J2

  Serial port 2               CN4      Reset switch                J3

  Serial port 1               CN5      Power LED                   J4

  VGA feature connector       CN6      Riser slot                  SL1

  Floppy drive interface      CN7

                        USER CONFIGURABLE SETTINGS

                Function                     Label           Position

     CMOS memory normal operation            JP1              Open

      CMOS memory clear                       JP1             Closed

     Monitor frequency select 31KHz         SW1/5             Off

      Monitor frequency select 40KHz         SW1/5              On

     Monitor type select color              SW2/3             Off

      Monitor type select monochrome         SW2/3              On

              DRAM CONFIGURATION

      Size          Bank 0          Bank 1

      4MB         (4) 1M x 9         None

      5MB         (4) 1M x 9     (4) 256K x 9

      8MB         (4) 1M x 9      (4) 1M x 9

      16MB        (4) 4M x 9         None

      20MB        (4) 1M x 9      (4) 4M x 9

      32MB        (4) 4M x 9      (4) 4M x 9

                        VIDEO MEMORY CONFIGURATION

          Size                    Bank 0                   Bank 1

          512KB                   512KB                     None

           1MB                    512KB                    512KB

  Note: The location of banks 0 & 1 are unidentified. The size of the
  video memory chips are unidentified.

  VIDEO MEMORY SWITCH CONFIGURATION

       Size               SW1/6

       512KB               On

        1MB                Off

        CPU TYPE SELECTION

    Type       SW2/1      SW2/2

  80486SX       Off        Off

  80487SX       On         Off

  80486DX       Off        Off

  80486DX2      Off        Off

                  VIDEO RESOLUTION SELECTION (800 X 600)

         Frequency                   SW1/1                  SW1/2

             56Hz                    Off                    Off

              60Hz                    Off                     On

              72Hz                    On                     Off

              56Hz                    On                      On

                  VIDEO RESOLUTION SELECTION (1024 X 768)

             Frequency                    SW1/3               SW1/4

             Interlaced                   Off                 Off

          60HZ non-interlaced              Off                 On

          70HZ non-interlaced              On                  Off

              Interlaced                   On                  On

                         ON BOARD VIDEO SELECTION

           Setting                    SW1/7                  SW1/8

             Enabled                   On                    Off

             Disabled                  Off                    On

