+---------------------------+
        | [N]ES [S]creen [A]rranger |
        +---------------------------+
        by SnowBro <kentmhan@online.no>

        Info:
        -----
        NSA is a development tool for NES programmers. It lets you
        load a .CHR file and an accompanying NES palette, arrange the
        tiles on the screen, and select the appropriate 4-color palette
        for each 2x2 tile grid. Great for making title screens and other
        fullscreen artwork, where you need to piece together a great
        amount of tiles and view the graphics in all their 4-bit glory.

        How to start it:
        ----------------
        You need to supply NSA with two files:

        1) a 4K .CHR file containing 256 NES tiles.
           These are the tiles you want to use for the artwork.
        2) a 16-byte palette in NES format.
           This file contains the NES color values you want to
           use for the picture.

        You then run the program by typing

        NSA <chrfile>

        Where <chrfile> is the .CHR filename, 4K in size (one Pattern
        Table). The palette should have the same name as the .CHR file,
        but with the extension .PAL. It will be loaded automatically. If
        the .PAL file is not present, the program will still continue to
        load, using a default palette for the colors. (From the "Kid
        Icarus" title screen, if you must know.) All the Name Table
        entries are set to $00. However, if an NSA output file (.NAM)
        of the same name as the .CHR file is present, it will be loaded
        instead.

        The interface:
        --------------
        Most of the screen is occupied by the Name Table itself, which is
        32x30 tiles in size. However, the video mode only allows me to
        display 25 rows, so use arrow keys Up/Down to view the whole NES
        screen. To the far right is the .CHR data, 8 tiles per row. Only
        176 tiles are viewable at one time; use PgUp/PgDown to scroll
        through the tile data. In the lower right corner is the currently
        selected tile displayed.

        How to work it:
        ---------------
        Use LEFT mouse button to select a tile from the .CHR data, then
        plot that tile at the appropriate position(s) in the Name Table.
        Press RIGHT mouse button to select the 4-color palette for that
        position in the Name Table. That's all there is to it. I've
        included the title screen from "The Legend of Zelda" to show
        what this program can do; edit it by typing "NSA ZELDA.CHR" at
        the DOS prompt (ZELDA.NAM will automatically be used as the
        Name Table+Attribute Table data).

        Output:
        -------
        To save your work, press F1. The output is in the form of a 1024
        bytes long binary file containing the Name Table tile index values
        and the Attribute Table. The output file will be saved as XXXXX.NAM,
        where XXXXX is the name of the CHR file. The format of the file is
        like so:

        000h-3BFh: Name Table
        3C0h-3FFh: Attribute Table

        Which means that the entire 1K-chunk can be written directly to
        NES PPU memory. Use a BIN2DB utility to convert the file to a
        series of byte definitions (.db), which you then can include into
        your NES code.

        Keys:
        -----
        Here's a summary of the keys you might want to strike at certain
        times:

        ESC       -   Exit program
        F1        -   Save data
        Up/Down   -   Scroll Name Table
        PgUp/PgDn -   Scroll .CHR bank

        Compression:
        ------------
        See "ntenc.txt".

        Final words:
        ------------
        Sorry for this crappy documentation; hope you can figure it out.
        If you have any questions, email me at kentmhan@online.no.
        If you need a tile editor for drawing the actual tiles, check
        out mine at http://home.sol.no/~kenhanse/nes.