TANDY/RADIO SHACK

2500 SX/20

Processor                  80386SX
Processor Speed            20MHz
Chip Set                   Unidentified
Video Chip Set             Unidentified
Maximum Onboard Memory     5MB
Maximum Video Memory       Unidentified
Cache                      None
BIOS                       Unidentified
Dimensions                 254mm x 218mm
I/O Options                Floppy drive interface, IDE interface, serial
                           port, parallel port, PS/2 mouse port, riser
                           slot
NPU Options                80387SX

[Image]

                                CONNECTIONS

  Purpose                  Location    Purpose                  Location

  Floppy drive               CN1       IDE interface LED           J1
  interface

  IDE interface              CN2       Riser slot                 SL1

  The location of the serial port, parallel port and PS/2 mouse port is
  unidentified.

                        USER CONFIGURABLE SETTINGS

                Function                     Label           Position

  »   Audio input source select               JP1           Pins 1 & 2
      microphone                                              closed

      Audio input source select line          JP1           Pins 2 & 3
      level                                                   closed

  »   Audio output source select              JP2           Pins 1 & 2
      headphone                                               closed

      Audio output source select line         JP2           Pins 2 & 3
      level                                                   closed

  »   Monitor type select VGA analog or       JP3           Pins 1 & 2
      standard multiple frequency                             closed

      Monitor type select non standard        JP3           Pins 2 & 3
      multiple frequency                                      closed

  »   VGA BIOS select PS/2 mode               JP4           Pins 2 & 3
                                                              closed

      VGA BIOS select AT mode                 JP4           Pins 1 & 2
                                                              closed

  »   Video IRQ9 disabled                     JP5              Open

      Video IRQ9 enabled                      JP5           Pins 1 & 2
                                                              closed

  »   On board video enabled                  JP6           Pins 1 & 2
                                                              closed

      On board video disabled                 JP6           Pins 2 & 3
                                                              closed

                            DRAM CONFIGURATION

       Size             Bank 0            Bank 1             Bank 2

       1.5MB              1MB          (2) 256K x 9           None

        2MB               1MB          (2) 256K x 9       (2) 256K x 9

        3MB               1MB           (2) 1M x 9            None

        5MB               1MB           (2) 1M x 9         (2) 1M x 9

            Note: Bank 0 is factory installed and is not configurable.
            The location is unidentified.