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Convert 15KHz to 30KHz?

    I have seen that someone tried to convert 15KHz horizontial sync to
30KHz horizontial sync from Apple IIgs' RGB to VGA monitor.  The trick is to
add blanking sync.  First line is displayed, second line is blanking, third
line is displayed, four line is blanking, and so forth until it reaches 400
lines.  It is like that displaying is odd and blanking is even.
    The convertor device receives 15KHz from Apple IIgs' RGB before it adds
another 15KHz as blanking.  It equals to 30KHz before it starts to display
on VGA monitor.  I am sure that mixing odd and even lines do not look good.
Someone did try to duplicate odd lines into even lines that is called double
line per single line.  It may be a clever trick, but it is very rare that no
one is doing a test yet.
    Did you test to work with LCD that supports 15KHz?

-- 
Bryan Parkoff


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6/12/2004 4:00:10 PM
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"Bryan Parkoff" <bryan.nospam.parkoff@nospam.com> wrote:

>    I have seen that someone tried to convert 15KHz horizontial sync to
>30KHz horizontial sync from Apple IIgs' RGB to VGA monitor.  The trick is to
>add blanking sync.  First line is displayed, second line is blanking, third
>line is displayed, four line is blanking, and so forth until it reaches 400
>lines.  It is like that displaying is odd and blanking is even.
>    The convertor device receives 15KHz from Apple IIgs' RGB before it adds
>another 15KHz as blanking.  It equals to 30KHz before it starts to display
>on VGA monitor.  I am sure that mixing odd and even lines do not look good.
>Someone did try to duplicate odd lines into even lines that is called double
>line per single line.  It may be a clever trick, but it is very rare that no
>one is doing a test yet.
>    Did you test to work with LCD that supports 15KHz?

There are (not cheap) devices with a technology called scan doubler that display
rgb (interlaced) 15 KHz signals  fine on a VGA monitor as (de-interlaced) 30 KHz
signals. 

Hans, http://www.hansotten.com
0
nobody1987 (62)
6/12/2004 4:46:28 PM
    Do you know where to find expensive device that has line doubler?

-- 
Bryan Parkoff

"Hans Otten" <nobody@yahoo.com> wrote in message
news:WTHLQOo1moGxzuVUWVkwhcjBhdQE@4ax.com...
> "Bryan Parkoff" <bryan.nospam.parkoff@nospam.com> wrote:
>
> >    I have seen that someone tried to convert 15KHz horizontial sync to
> >30KHz horizontial sync from Apple IIgs' RGB to VGA monitor.  The trick is
to
> >add blanking sync.  First line is displayed, second line is blanking,
third
> >line is displayed, four line is blanking, and so forth until it reaches
400
> >lines.  It is like that displaying is odd and blanking is even.
> >    The convertor device receives 15KHz from Apple IIgs' RGB before it
adds
> >another 15KHz as blanking.  It equals to 30KHz before it starts to
display
> >on VGA monitor.  I am sure that mixing odd and even lines do not look
good.
> >Someone did try to duplicate odd lines into even lines that is called
double
> >line per single line.  It may be a clever trick, but it is very rare that
no
> >one is doing a test yet.
> >    Did you test to work with LCD that supports 15KHz?
>
> There are (not cheap) devices with a technology called scan doubler that
display
> rgb (interlaced) 15 KHz signals  fine on a VGA monitor as (de-interlaced)
30 KHz
> signals.
>
> Hans, http://www.hansotten.com


0
6/12/2004 5:04:07 PM
    Do you know where to find expensive device that has line doubler?

-- 
Bryan Parkoff

"Hans Otten" <nobody@yahoo.com> wrote in message
news:WTHLQOo1moGxzuVUWVkwhcjBhdQE@4ax.com...
> "Bryan Parkoff" <bryan.nospam.parkoff@nospam.com> wrote:
>
> >    I have seen that someone tried to convert 15KHz horizontial sync to
> >30KHz horizontial sync from Apple IIgs' RGB to VGA monitor.  The trick is
to
> >add blanking sync.  First line is displayed, second line is blanking,
third
> >line is displayed, four line is blanking, and so forth until it reaches
400
> >lines.  It is like that displaying is odd and blanking is even.
> >    The convertor device receives 15KHz from Apple IIgs' RGB before it
adds
> >another 15KHz as blanking.  It equals to 30KHz before it starts to
display
> >on VGA monitor.  I am sure that mixing odd and even lines do not look
good.
> >Someone did try to duplicate odd lines into even lines that is called
double
> >line per single line.  It may be a clever trick, but it is very rare that
no
> >one is doing a test yet.
> >    Did you test to work with LCD that supports 15KHz?
>
> There are (not cheap) devices with a technology called scan doubler that
display
> rgb (interlaced) 15 KHz signals  fine on a VGA monitor as (de-interlaced)
30 KHz
> signals.
>
> Hans, http://www.hansotten.com


0
6/12/2004 5:05:25 PM
"Bryan Parkoff" <bryan.nospam.parkoff@nospam.com> wrote:

>    Do you know where to find expensive device that has line doubler?

Do a google search for : rgb scan doubler

Hans, http://www.hansotten.com
0
nobody1987 (62)
6/12/2004 5:16:17 PM
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