Info about the C64 prolly noone is interested in

The Commodore 64 was the first computer I had. Me and my brother got it when I was 8, which was 1988.
I did not do any graphics on it back then, I just played games - ahh the memories :)
Later when we got an Amiga 500 we sold the C64, a thing I regreted many years later.

Sometime in 2004 I kinda lost interest in pixelart temporarily, I just didn't really enjoy it anymore.
When I chatted with a good online friend, Helm, about it, we talked about new things to try out.
Somehow the idea of making art like it would have looked on the C64 came up and we went right at it.
I looked up some infos about the C64's graphicsmodes, gave the info to Helm and we started pixeling away.

The result was the picture below.

There is a graphicsmode called FLI ( Flexible Line Interpretation ), which we believed the pictures we created were true to.
We thought in FLI it was possible to use all 16 colors the machine has at free will, which we later found out is not the case.
How the FLI mode works is a bit more complicated and the source of our original info about it was simply wrong.

After finding out about this, we figured making FLI pictures without a real C64 would be rather tedious.
This is because one would have to keep the strange restriction bends this mode uses in mind, which would lead to
editing the image over and over again, to finally make them fit the capabilities of the FLI mode.

Then we had a better idea: Multicolor Mode, also simply called Mcol or Koala, because of the popular C64 paint program Koala Paint.
Basically Mcol is, together with Hires Mode, the native graphics mode of the C64.
It has stricter limitations than FLI, which basically is a hacked version of Mcol,
but it is much easier to replicate without an actual C64.

Let's take a look at some of the C64 restrictions regarding graphics.

The palette:

First of all, there is no such thing as a "true" C64 palette, as there are slight variations on each C64.
This is due to the fact that the color informations are handled via resistors and the resistance values vary a bit from unit to unit.

Hover the cursor over any of the palettes to see it applied to the picture above.

The palette I use		greyscaled
Pepto palette		greyscaled
Vice palette		greyscaled
CCS64 palette		greyscaled

As you can see the differences between the upper two palettes are minor.
It's very similar to the palette Philip 'Pepto' Timmermann made, just a bit brighter and a tiny bit more saturated.
If you look at the greyscale versions of those two you see that there are black and white and 7 shades of grey.
This is what the picture looked on a b/w television set back in the days, maybe a bit more blurred :D.
The point is that these palettes keep the right luminance ratios and the colors seem true to the original as well.
The Pepto one seems closer to the original C64, but I like the brighter one a bit more, but that's just preference.

The third one is the default palette of VICE, a popular C64-emulator.
It's way too saturated and also messes up the luminance values a bit.
You get 16 more or less distinguishable greys on the greyscale version, but that is not the case on a real C64.

The fourth palette, taken from CCS64, another C64 emulator, is downright horrid and completely flawed.
It has both messed up luminance values and colors, with some colors ( esp. the light grey ) being totally mutilated.
When you look at the greyscale version it has about 5 distinguishable values, maybe a few more if you look hard enough.
This is not really honest to the real c64, and if you use CCS64 ( quite a good emulator actually ), I would suggest setting another palette.

Check this article by Philip 'Pepto' Timmermann if you want to have more detailed info about the C64 colours.

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Info about C64 graphic modes (the ones I use)

Multicolour Bitmap - Mcol:

The resolution is 160x200 with horizontally more or less doubled pixels, so one ends up with a resolution of 320x200 on a PC.
This mode, like all other C64 modes can make use of all the 16 colors the C64 has to offer ( and that was enough back then ).
Now the tricky part:

The picture is split up into 4x8 pixel characters ( meaning 8x8 pixels on the pc ) set up in 40 columns and 25 rows.
Each of these 1000 characters can have a maximum of 4 out of the 16 available colors. So far so good.
The trick is that one color, the so called background color, is global for the whole image. This color can be any of the 16 C64 colors.
In effect this means that if a character has 4 colors one of them has to be the background color.

Here some examples:

The backgoundcolor would be black here, since it is a character from the above image.

  This is the original char. 3 colors plus black, works.

  This one would not work as it has more than 4 colors.

  And this one would not work as it has 4 colors, but none of them is black.

Hires Bitmap - Hires:

The resolution is 320x200 and the "only" restriction is that one can only use 2 colours in each 8x8 character.

I will add more info of other modes as soon as I release a picture that utilises them :)