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Software 2000 Volume 1 (Disc 1 of 2).iso
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Colors
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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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