
                       NS486SXF Assembly Code - README                        
                       -------------------------------
 
                             December 2, 1996

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This directory contains three subdirectories with Assembly code for the
NS486SXF.

The NS486SXF evaluation board has a flash resident Target Loader which
performs basic setup of the board before vectoring to an application.
This includes CPU and DRAM setup, CPU Speed detection, and DRAM Size
determination.

The software in these subdirectories is sample code similar to what is
performed by the Target Loader.  This code can also be run from the
Flash Loader for demonstration purposes.

CONTENTS
--------

  BOILER\ - This is an assembly (MASM) program that performs NS486SXF and
            evaluation board setup, as well as proper protected mode
            setup (GDT, IDT).  Also included is a simple program to show
            that the setup is working, by printing UART messages.
            This is a useful reference on how to configure the NS486SXF
            and the evaluation board.  The "README.TXT" file in this
            directory provides additional information.  

  CPUSPEED\ - This assembly code determines the CPU Speed of the NS486SXF
              evaluation board using the board's external UART and the
              NS486SXF's timer.  The Target Loader does this on already.
              However, custom board designs may want to use this code as
              a sample of how to determine the CPU Speed (if you wish to
              support dynamic determination of CPU Speed in your
              application.)  The file "README.TXT" in this directory
              contains additional information.

  DRAMSIZE\ - This assembly code determines the DRAM SIMM size on the
              NS486SXF evaluation board.  This code only supports 1, 4, and
              16MB SIMMs (the only SIMMs the evaluation board supports)
              and relies on how the DRAM is setup on the evaluation
              board.  This code can serve as an example of DRAM size
              determination for custom board designs.  The file "README.TXT"
              in this directory contains more information.

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