Software 2000/Software 2000 Volume 1 (Disc 1 of 2).iso/utilities/u600.dms/in.adf/Doc/Colors

Text File | 1991-10-02 | 18.5 KB | 442 lines

COLOR SCREEN

    KEY SEQUENCE: [RIGHT AMIGA] [C] (Colors)

    The COLORS menu option allows you change A64's colors and the
    number of colors A64 uses to draw the C64's screen.

    Before explaining the COLORS option we must first explain a
    little bit about the Commodore 64's colors and how it uses them.
    The Commodore 64 is capable of displaying a maximum of 16 colors
    at any one time.  On the C64 you are not able to change its
    colors, they are always displayed the same (Until now!).  The C64
    uses numbers to signify its colors.  These color numbers range
    from 0 to 15.  The C64's color numbers and their corresponding
    colors are as follows:

    0 = BLACK      4 = PURPLE       8 = ORANGE      12 = MED GRAY
    1 = WHITE      5 = GREEN        9 = BROWN       13 = LGT GREEN
    2 = RED        6 = BLUE        10 = LGT RED     14 = LGT BLUE
    3 = CYAN       7 = YELLOW      11 = DARK GRAY   15 = LGT GRAY

    When selecting the COLORS menu option a screen will open at the
    bottom of the A64 Prefs screen.  This screen has many gadgets
    that allow you to control A64's colors.  The color screen's
    gadgets will be explained by separating them into sections.
    Please note that most of the color screen's gadgets interact with
    each other.  If you change the setting of one gadget it will
    probably change the setting of one or more other gadgets, because
    of this we suggest that you read this section of the manual in
    order, without jumping from section to section.  The color
    screen's gadgets and their functions are as follows:

COLOR GADGETS

    The COLOR GADGETS are the 20 small gadgets that start at the top,
    left hand side of the screen.  These gadgets represent A64's
    current color palette, with each gadget containing one of A64's
    colors.  These COLOR GADGETS allow you to select a color that you
    want to change.  The current selected gadget will be displayed
    with a red square around it.  You will note that there are 20
    gadgets, while the C64 only has 16 colors.  This is because A64
    needs other colors, in addition to the C64's 16 colors, for some
    of it's COLOR MODES (COLOR MODES are discussed in the following
    sections).  To explain this we need to define what C64 colors are
    represented by each COLOR GADGET.  Going left to right, the first
    COLOR GADGET represents the C64's current background color.  The
    background color is the color of the screen that doesn't contain
    any graphics data, the transparent part of the screen.  For those
    of you that know a little about the C64's graphics, the C64's
    background color is stored in the color register at 53281.  The
    actual color this gadget contains depends on what COLOR MODE you


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    are using.  If you are using 16 or 20 COLOR MODE, this gadget
    will contain a mirror image of one of the C64's 16 colors (it
    will contain the same color as one of the other gadgets).  If you
    are using one of the other COLOR MODES: 2, 4, or 8, then it will
    contain it's own independent color.  The next 16 gadgets
    represent the C64's 16 colors, with the first gadget representing
    the C64's color 0 and the last gadget, of the 16, representing
    the C64's color 15.  The last three color gadgets are only used
    for A64's 20 COLOR MODE.  They represent three of the C64's color
    registers that are used for two of it's graphics modes.  For the
    people who know a little bit about the C64's graphics, the C64
    color registers are at 53282-53284 and are used for multicolor
    text and extended background color text modes.  These three
    gadgets are like the background color gadget and will contain a
    mirror image of one of the C64's 16 colors.

    The four gadgets described above, the background color gadget and
    the three gadgets used by 20 COLOR MODE, are different from the
    other 16 COLOR GADGETS.  While the other 16 COLOR GADGETS
    represent actual C64 colors that the C64 can not change, these
    four gadgets represent color registers within the C64 that can be
    changed to any one of the C64's 16 colors.  Seeing how the C64
    can change the color in these registers, thus changing the color
    in the gadgets that represent them, any changes you make to these
    gadgets will be temporary.  If you want to change one of these
    four gadgets and have its color preserved when A64 is re-entered
    you must find the other gadget (in the other 16 gadgets) that
    contains the same color as the gadget you want to change and then
    modify that gadget to the color you want.  For example, using the
    default C64 colors, the background color gadget will contain the
    color blue and will be a mirror image of the seventh COLOR GADGET
    which will also contain the color blue.  If you change the color
    of the seventh COLOR GADGET to white and then re-enter A64, the
    background color will be changed to white, the color you selected
    in the seventh COLOR GADGET.  If you had only changed the color
    in the background color gadget and re-entered A64 the background
    color would be changed back to blue, the color in the seventh
    COLOR GADGET.  For most applications you can ignore these four
    color gadgets and change the other 16 color gadgets to the colors
    you want, but having the ability to change these four color
    gadgets can be useful when saving screens as IFF files.

    NOTE: When selecting a COLOR MODE of less than 20, all unused
          COLOR GADGETS will be disabled.

SLIDER GADGETS

    The SLIDER GADGETS are the three long, multicolored gadgets
    located below the COLOR GADGETS.  These gadgets are used to
    change A64's colors.  More specifically, they allow you to change
    the color contained in the selected COLOR GADGET.  On the Amiga,
    colors are formed by adding a combination of RED, GREEN and BLUE


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    color parts.  These SLIDER GADGETS represent these three color
    parts with; RED on top, GREEN in the middle and BLUE on the
    bottom.  Each one of these gadgets contain 16 different colors.
    By selecting one of these colors you will change the selected
    COLOR GADGET to that color.  You will note that every time you
    select a color that all the colors in the SLIDER GADGETS will
    change, this is to show what new colors are available within a
    certain range from the color you just selected.  All of the
    Amiga's 4096 possible colors can be achieved by changing the
    settings of these three gadgets.

COLOR MODE GADGET

    The COLOR MODE gadget is the located at the top, right hand side
    of the color screen.  It is shown by the words "COLOR MODE:"
    followed by a gadget containing a number.  This gadget allows you
    to pick how many colors A64 will use to draw the C64 display.
    The possible settings are: 2, 4, 8, 16 and 20.  Each setting
    corresponds to the number of colors that A64 will use.  These
    color modes also relate to how many bitplanes are used to make
    the C64 display. The Amiga uses bitplanes to make up its screens.
    You do not need to fully understand bitplanes to grasp this
    example, but what you should understand is that the more
    bitplanes that are used, the more colors that can be displayed at
    one time and the more work A64 has to do to display them.  By
    lowering the number of bitplanes, you lower the number of
    available colors, but also decrease the amount of work A64 has to
    do to draw the screen, resulting in A64 running faster.  The
    following chart shows you how many colors the Amiga is capable of
    displaying for a certain number of bitplanes and how many colors
    A64 will display for the same number of bitplanes:

        NUMBER OF        NUMBER OF           NUMBER OF
        BITPLANES        AMIGA COLORS        A64 COLORS
        ---------        ------------        ----------
            1                 2                   2
            2                 4                   4
            3                 8                   8
            4                16                  16
            5                32                  20

20 COLOR MODE

    There are only 16 colors on the C64, but because of differences
    in the way that the Amiga and the C64 make their screens A64 uses
    more than 16 colors to display all of the C64's colors.  In
    addition to the C64's 16 colors, A64 needs one color for the
    background color and it also uses three additional colors for two
    of its graphics modes (See COLOR GADGETS in the COLORS section).
    That brings our total up to 20 colors needed for A64 to draw the
    C64's screen.  That's how we get 20 COLOR MODE.  When using this


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    COLOR MODE A64 can replicate the C64's screen perfectly.  The
    confusion starts when we start changing the COLOR MODE and
    lowering the number of bitplanes.  When we start lowering the
    COLOR MODE, we start losing colors.  A64 handles this slightly
    different for 16 COLOR MODE than it does for the 2, 4 & 8 COLOR
    MODES.  We will explain this by separating 16 COLOR MODE from the
    2, 4 & 8 COLOR MODES and explaining them separately.

16 COLOR MODE

    With 16 COLOR MODE A64 uses four bitplanes.  This allows us to
    have a maximum of 16 colors, exactly the number the C64 has, but
    remember A64 needs other colors.  A64 needs a maximum of 20
    colors and we now only have 16, four colors short.  A64 handles
    this by replacing the missing colors with other available colors.
    The first colors A64 can replace are the three colors mentioned
    above, that were needed for two of A64's graphics modes.  These
    three colors are only used for 20 COLOR MODE and can be ignored
    for all other COLOR MODES.  Getting rid of these three colors
    brings our total colors, needed by A64, down to 17.  This still
    leaves us one color short.  The way A64 handles this, is to
    replace one of the C64's colors.  A64 replaces the C64's color 15
    (light gray) with the C64's color 1 (white).  This means, when
    using 16 COLOR MODE, whenever something is supposed to be
    displayed in color 15 it will be displayed in color 1.  This
    replacement was picked, because the default color 1 (white) looks
    very close to the default color 15 (light gray).  For all
    practical purposes, this is the only difference between 16 COLOR
    MODE and 20 COLOR MODE.  With 16 COLOR MODE all colors will look
    the way they should, except color 15 will be replaced with color
    1.

2, 4 & 8 COLOR MODES

    The remaining three COLOR MODES: 2, 4 & 8, are all handled by A64
    in the same way.  With these COLOR MODES A64 must replace more
    colors, the lower the color mode, the more colors that need to be
    replaced.  The way A64 does this is by taking the number of
    allowed colors (the COLOR MODE number) and reserving one color
    for the background color and using the remaining colors for the
    C64 colors.  Because of the limited number of colors provided by
    these COLOR MODES A64 sets aside one color for the background
    color that can be different than all the remaining colors, this
    is different than the 20 & 16 color modes, where the background
    color is always a copy of one of the C64's colors. For example,
    in 8 COLOR MODE, A64 uses 1 color for the background color,
    leaving 7 colors free for C64 colors.  In 4 COLOR MODE, A64 uses
    1 color for the background color, leaving 3 colors free for C64
    colors and in 2 COLOR MODE A64 uses 1 color for the background
    color, leaving 1 color free for C64 colors (this is the
    equivalent of a monochrome mode).  The following chart shows what


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    colors are replaced by these COLOR MODES:

        The 2, 4 & 8 COLOR MODE numbers correspond to the COLOR
        GADGETS starting with the second gadget in, from the left
        (skip the 1st color gadget, the background color gadget).

        C64 COLOR    8 COLOR MODE    4 COLOR MODE    2 COLOR MODE
        ---------    ------------    ------------    ------------
            0             1               1               1
            1             2               2               1
            2             3               3               1
            3             4               1               1
            4             5               2               1
            5             6               3               1
            6             7               1               1
            7             1               2               1
            8             2               3               1
            9             3               1               1
           10             4               2               1
           11             5               3               1
           12             6               1               1
           13             7               2               1
           14             1               3               1
           15             2               1               1

    The different COLOR MODES supported by A64 may seem very
    confusing, but they are really not that complicated once you
    start using them.  Included with The A64 package is a C64 program
    named "64Colors."  It is located on disk #1 in the directory
    "64Prgs."  We suggest you use this program and experiment with the
    different COLOR MODES to see their effect on the C64's colors.

    Each COLOR MODE has its own color palette containing the number
    of colors supported by the COLOR MODE (i.e., 16 COLOR MODE has
    its own palette of 16 colors).  If you have made any changes to
    to the colors and then change COLOR MODES you will be prompted
    with a requester asking you if you want to to keep the changes
    made.  Select YES to preserve the changes, NO to change COLOR
    MODES without saving your changes or CANCEL to abort changing
    COLOR MODES.

    The drawing of the C64's screen is the most time consuming part
    of A64.  The general rule is that the more graphics a C64 program
    uses, the more work A64 has to do to display them and the slower
    A64 will run the C64 program.  You can help compensate for this
    extra work, by lowering the COLOR MODE.  When you lower the COLOR
    MODE you decrease the number of bitplanes that A64 has to draw to
    making A64 run faster.  We strongly recommend that you lower the
    COLOR MODE to at least 16 whenever possible.  16 COLOR MODE will
    handle most C64 programs with no dramatic decrease in color
    resolution.  Also note that if you are running an A500 or A2000


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    with only 1mb RAM selecting 16 COLOR MODE, which eliminates the
    5th bitplane and will give you a noticeable speed increase.

    NOTE: In almost all cases the lower the COLOR MODE the faster A64
          will run, but with certain programs that use the C64
          graphics modes Multicolored Text or Extended Background
          Color Text A64 will run faster in 20 COLOR MODE.  You can
          determine if a C64 program is using one of these graphics
          modes by using the VICDump command in A64Mon.

RESET GADGET

    The RESET GADGET allows you to reset all of the colors to either
    their original or last values.

    When selecting the RESET GADGET you will be prompted with a
    requester containing three gadgets.  The function of these
    gadgets are as follows:

    DEF, selecting this gadget will reset all of the colors to their
    original settings.

    LAST, selecting this gadget will reset all of the colors to their
    last saved settings.  This will either be the settings set when
    A64 was 1st loaded or if you have changed some of the colors and
    preserved them, it will be the preserved settings.

    CANCEL, will abort the operation.

    NOTE: The RESET GADGET effects all COLOR MODES.

SPREAD GADGET

    The SPREAD GADGET allows you to spread the colors between two
    COLOR GADGETS.

    When selecting the SPREAD GADGET the mouse pointer will change
    to an arrow with the word "TO" under it.  You should then select
    the COLOR GADGET you wish to spread to.  Selecting any other
    gadget besides a COLOR GADGET will abort the operation.

    NOTE: You can only do a spread between the main 16 COLOR GADGETS.

EXCH GADGET

    The EXCH GADGET allows you to exchange the colors between two
    COLOR GADGETS.

    When selecting the EXCH GADGET the mouse pointer will change
    to an arrow with the word "TO" under it.  You should then select
    the COLOR GADGET you wish to exchange with.  Selecting any other


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    gadget besides a COLOR GADGET will abort the operation.

COPY GADGET

    The COPY GADGET allows you to copy the COLOR from one COLOR
    GADGET to another COLOR GADGET.

    When selecting the COPY GADGET the mouse pointer will change
    to an arrow with the word "TO" under it.  You should then select
    the COLOR GADGET you wish to copy the selected COLOR GADGET's
    color to.  Selecting any other gadget besides a COLOR GADGET will
    abort the operation.

UNDO GADGET

    The UNDO GADGET allows you to undo any changes you made to the
    COLOR GADGETS.

    When selecting the UNDO GADGET any changes to the COLOR GADGETS,
    (since a COLOR GADGET was selected) will be "undone."

OK AND CANCEL GADGETS

    Selecting OK will preserve all changes to the Color Screen's
    settings and return you to A64 Prefs.

    Selecting CANCEL will ignore any changes to the Color Screen's
    settings and return you to A64 Prefs.

    NOTES: CANCEL will not cancel out changes to the COLOR MODE
           setting itself nor will it restore changes made to another
           COLOR MODES' colors if you preserved them.

           You may notice when running some programs that when you
           enter A64 Prefs the background changes color, this is
           normal.  This can happen if a C64 program is using a
           graphics technique called "raster interrupts" and the
           background color is different in areas on the same screen.
           Because A64 Prefs does not support multiple background
           colors on the same screen, as A64 does, A64 Prefs will
           display the last background color used by A64 for its
           background color.











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