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Is there an easy way to "de-interlace" the Characater Definition tables at $800 — Parallax Forums

Is there an easy way to "de-interlace" the Characater Definition tables at $800

BeanBean Posts: 8,129
edited 2006-11-27 02:19 in Propeller 1
Is there an easy way to de-interlace the dot patterns·?
I'm working in assembly.

Bean.


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·

Comments

  • CJCJ Posts: 470
    edited 2006-11-26 23:22
    I would imagine a peek into the tv text and tv driver set would get you the info you need

    or perhaps

    read the long
    and it with an even/odd bit pattern
    rotate left 2
    test it with #3
    use the flags and conditional execute for set/not set

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    Who says you have to have knowledge to use it?

    I've killed a fly with my bare mind.
  • BeanBean Posts: 8,129
    edited 2006-11-26 23:49
    All of the video drivers use 4 color mode. I guess that's why the characters are interlaced in the first place.
    The problem is that the bits need to be rotated a different number of times.
    If I want the pattern that start with bit0, then bit2 needs rotated once(to become bit1), bit4 need rotated twice(to become bit 2), bit6 needs rotated three times(to become bit 3), and so on.
    I just don't see an easy way to convert from interlaced to non-interlaced.

    I could just create my own character set, but it seems like such a waste when one already exists.

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com
    Stuff I'm selling on ebay http://search.ebay.com/_W0QQsassZhittconsultingQQhtZ-1

    "People who are willing to trade their freedom for·security deserve neither and will lose both." Benjamin Franklin
    ·
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2006-11-27 00:03
    Bean,

    Could you work with the character defs if the bits were doubled instead of interlaced? What I'm thinking is something like this:

                 [b]rdlong[/b] char_def,char_ptr
             [b]mov[/b]   scr,char_def
             [b]and[/b]    char_def,_0x55555555   ' or _0xaaaaaaaa, depending of even/odd character.
             [b]and[/b]    scr,_0x55555555
             [b]rol[/b]    scr,#1 ' ror for _0xaaaaaaaa
             [b]or[/b]    char_def,scr
             ...
_0x55555555 [b]long[/b] $55555555


    -Phil

    Post Edited (Phil Pilgrim (PhiPi)) : 11/27/2006 12:08:49 AM GMT
  • BeanBean Posts: 8,129
    edited 2006-11-27 00:05
    Phil,
    I'm using the video hardware, but I need to use 2 color mode. If I double the pixels I need to update WAITVID twice as fast. But it may be an option. I'll keep it in mind.

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com
    Stuff I'm selling on ebay http://search.ebay.com/_W0QQsassZhittconsultingQQhtZ-1

    "People who are willing to trade their freedom for·security deserve neither and will lose both." Benjamin Franklin
    ·
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2006-11-27 00:20
    Bean,

    If you're using the video hardware, what would be wrong with using four-color mode with two colors? You'd have to service WAITVID twice as fast, granted, but there'd be no fussing with the bits. For even characters (those using MSB of character data), your color bytes (dest of WAITVID) would look like this:

    ··Color1:Color1:Color0:Color0

    And for odd characters, like this:

    ··Color1:Color0:Color1:Color0

    -Phil
  • BeanBean Posts: 8,129
    edited 2006-11-27 00:29
    Hmmm, Good idea.
    Since the processing is minimal, I think it might work.
    Thanks Phil.

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com
    Stuff I'm selling on ebay http://search.ebay.com/_W0QQsassZhittconsultingQQhtZ-1

    "People who are willing to trade their freedom for·security deserve neither and will lose both." Benjamin Franklin
    ·
  • Beau SchwabeBeau Schwabe Posts: 6,547
    edited 2006-11-27 01:35
    Bean,

    The "formula" that I have been using can be found at this thread...

    http://forums.parallax.com/showthread.php?p=611628

    An assembly implementation of this can be found in the VGA text and graphics object...

    http://forums.parallax.com/showthread.php?p=606957

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • BeanBean Posts: 8,129
    edited 2006-11-27 02:19
    Thanks Beau,
    I just remembered that the video data is a bitmap. So the de-interlacing will NOT be done by the cog that is generating the video.
    I'll check out the links you provided.

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Cheap used 4-digit LED display with driver IC·www.hc4led.com

    Low power SD Data Logger www.sddatalogger.com
    SX-Video Display Modules www.sxvm.com
    Stuff I'm selling on ebay http://search.ebay.com/_W0QQsassZhittconsultingQQhtZ-1

    "People who are willing to trade their freedom for·security deserve neither and will lose both." Benjamin Franklin
    ·
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