Text 14576, 105 rader
Skriven 2007-04-23 22:05:46 av mark lewis (1:3634/12.0)
  Kommentar till text 14366 av MICHAEL LOO (1:123/140)
Ärende: CRIMINY 399
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 MLoo> 16.7 million colors is the standard claim nowadays I 
 MLoo> understand. I don't even know the names of 16.7 million 
 MLoo> colors, not to mention not being able to see them (and 
 MLoo> my color vision is okay).

 GJ> What a ridiculous claim!  Although I don't fully understand current
 GJ> methods of achieving colours on screens, I feel that in a small area,
 GJ> such colour variation would be impossible.  It sounds equivalent to
 GJ> changing one pixel in an entire screen.

 MLoo> It's different than that to me.

i'll stop there and try to take it from the bottom...

remember the old 80x25 screen? all text? with just monochrome text, that is
2000 characters... when they came out with color capabilities, they doubled
that so that one byte was the character and the other byte was the color of
that text... 4000 bytes for the visible screen... they had also added "screen
pages" so that one could fill them with the necessary data and then just change
the visible page making the whole transition virtually instantaneous...

then they came up with graphics modes... these also started as 80x25 block type
characters... some of these could be made of rows of dots such that the
foreground of the block character was one color and the background was
another... these were the first dithered colors... as things progressed, we
went from CGA to EGA and then VGA... there is/was also XGA which was, IIRC, a
subset of VGA... as we moved to each one, the videocards needed more and more
memory to hold all the additional "blocks" now known as pixels... the more
pixels, the more memory needed... we went from 8bit (one byte) color to 16bit
(two bytes) and then to 24bit and 32bit (three bytes and four bytes)... each
stage, CGA, EGA, VGA, also gave us higher resolutions and capabilities... i
generally describe "resolution" like this...

  imagine yourself in a helicopter 25 feet over your house.
  all you can see, basically, is your house.
  now, raise up to 250 feet.
  now you can see your entire block.
  your house appears smaller but isn't.
  now raise to 2500 and you can see many blocks.
  your house is still the same size as it ever was.

this was most commonly given to those complaining of the icons being too small
on the screen and they didn't understand why... many didn't know that the
resolution was x when they had maybe been used to viewing in y... this was also
very common when folk upgraded their systems without upgrading their old 14inch
or 15inch monitor... yes, higher resolutions on those are quite small ;)   

in the old 8bit mode, we had 256 representations of the colors... this is
because with eight 1's (ones) and 0's (zeros), we can only count from 0 (zero)
to 255... zero is a number and thus we have 256... 16bit stuff brought us 65536
colors... 256*256... when 24bit stuff came out, that was probably the most
advantageous as far as coding was concerned... this mainly due to the RGB
layout that i spoke of in earlier messages...

way back when, 640x480 was a common screen resolution... with only 256 colors,
that is/was 640*480=307200 307200*256=78643200 78643200/8=9830400 so we're
looking at 9Meg of memory just to store that one entire screenfull of 256
colors... 4Meg videocards were the shizzit but only with _16_ colors...

800x600 was the next major screen resolution which required 15360000 (15Meg) of
RAM for 256 colors on the _videocard_... this mode worked just fine for
machines with 16Meg videocards... i'm sure that many of us can remember those
days ;)

most machines come configured at 1024x768 screen resolution these days... if
you were playing with computers back when win v3.xx was out, you may remember
the blocky look and only 16 colors available... these days, we have much
smoother graphics as well as a lot more colors available...

my current video card has 256Meg on it which is the same as what this machine
has in it... 256Meg for the video capabilities alone... i'd have never thought
it! ;)  but, one must also look to the chips used on today's graphics cards...
they are dedicated CPUs with their own microcode and BIOS specifically for
doing graphics work... there are projects out there that try to take advantage
of the extra processing power of the GPU (graphic processin unit) since they,
like the CPU, sit in idle mode for a major portion of their time...

i've been looking on the 'net while writting this to see if i could locate a
screen of 24bit color... sadly, i haven't been able to locate what i'm looking
for... a picture is worth a thousand words and so far, the closest thing i've
found is the graphic at the bottom of http://www.color.org/sRGB.html

it looks like i may have to create something to fulfill this discussion so
possibly i'm off to my compiler and source code for a day or so O:) it is
probably easier and faster to create a program to draw a HTML table starting
from #000000 and going to #ffffff by ones than it is to sit and manually create
it ;)

it is possible that http://www.midnightkite.com/color.html will depict more of
what i'm trying to describe but as i also know that many pics on the 'net are
GIFs, i also know that GIFs are limited to 256 colors which knocks them out of
usability in demonstration... i think that a chart will be the best bet,
overall... of course, this will also depend on your video settings ;)

what i'm really searching for is something that many of us have likely seen if
we've ever run any diagnostic programs, on our systems, that test the video
card's capabilities... generally it has been seen as a fullscreen where the
left side is the darker colors and the right is the brighter with an appearance
of triangles pointing to the left that get darker as they get smaller...

i'll find something, one way or another ;)

)\/(ark

 * Origin:  (1:3634/12)