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Flavioweb
Registered: Nov 2011 Posts: 463 |
$3FFF border Idle pattern -mode- and color.
There is a way to change the color and/or -mode- (multicolor/ECM/whatever instead hires) of the IDLE pattern ($3FFF) that appears when you open upper/lower border? |
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Smasher
Registered: Feb 2003 Posts: 520 |
good question. AFAIK no. it's just black, if you want colors: sprites or background.
but I'm a lamer, so I could be wrong... :) |
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Oswald
Registered: Apr 2002 Posts: 5094 |
guess so too, illegal mode "mode" change is possible tho, but you can only read the pixels via HW sprite collision :) |
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JackAsser
Registered: Jun 2002 Posts: 2014 |
Only thing that you can change is mode. In ECM-mode the IDLE byte is fetched from $37FF instead. |
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Smasher
Registered: Feb 2003 Posts: 520 |
<troll_mode> $39ff?... :) </troll_mode> |
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lft
Registered: Jul 2007 Posts: 369 |
The various options are pretty thoroughly described in the vic article. Whatever data that would normally be obtained from the video matrix is going to be $00. So if you pick hires bitmap, for instance, then every pixel will be black regardless of d021 and the value of the idle byte. |
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Smasher
Registered: Feb 2003 Posts: 520 |
Quote: The various options are pretty thoroughly described in the vic article. Whatever data that would normally be obtained from the video matrix is going to be $00. So if you pick hires bitmap, for instance, then every pixel will be black regardless of d021 and the value of the idle byte.
said with different words: find the way to put some colors on those black pixels and next nobel's prize is yours! :) |
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Oswald
Registered: Apr 2002 Posts: 5094 |
"Whatever data that would normally be obtained from the video matrix is going to be $00. "
iirc, its not 00, just colors are strict black. with sprite HW collision the gfx is still readable. |
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chatGPZ
Registered: Dec 2001 Posts: 11386 |
its 0, which is what makes it black in the first place :) |
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Oswald
Registered: Apr 2002 Posts: 5094 |
first, $00 from the video matrix is only black if any associated color (register) is black....
secondly its not $00, VIC article:
3.7.3.6. Invalid text mode (ECM/BMM/MCM=1/0/1)
----------------------------------------------
Setting the ECM and MCM bits simultaneously doesn't select one of the
"official" graphics modes of the VIC but creates only black pixels.
Nevertheless, the graphics data sequencer internally generates valid
graphics data that can trigger sprite collisions even in this mode. By
using sprite collisions, you can also read out the generated data (but you
cannot see anything, the screen is black). You can, however, only
distinguish foreground and background pixels as you cannot get color
information from sprite collisions. |
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JackAsser
Registered: Jun 2002 Posts: 2014 |
Quote: first, $00 from the video matrix is only black if any associated color (register) is black....
secondly its not $00, VIC article:
3.7.3.6. Invalid text mode (ECM/BMM/MCM=1/0/1)
----------------------------------------------
Setting the ECM and MCM bits simultaneously doesn't select one of the
"official" graphics modes of the VIC but creates only black pixels.
Nevertheless, the graphics data sequencer internally generates valid
graphics data that can trigger sprite collisions even in this mode. By
using sprite collisions, you can also read out the generated data (but you
cannot see anything, the screen is black). You can, however, only
distinguish foreground and background pixels as you cannot get color
information from sprite collisions.
Illegal mode != ghostbyte |
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chatGPZ
Registered: Dec 2001 Posts: 11386 |
Quote:first, $00 from the video matrix is only black if any associated color (register) is black....
read again what lft wrote. hires bitmap -> vram is directly related to color. and yes, its 0 :) (and thats also the case for illegal gfx mode, when BMM is selected. whether valid pixel data is still produced is completely unrelated) |
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Oswald
Registered: Apr 2002 Posts: 5094 |
okay, not really knew wtf is video matrix, in my mind it could be anything bitmap or screen, but google shows its what I usually call screen or attribute memory. |
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Digger
Registered: Mar 2005 Posts: 437 |
You can (obviously!) change the color by inverting whatever $3fff pattern you got and use $d021. |