Re: Convert 15KHz to 30KHz?

["Bryan Parkoff" <bryan.nospam.parkoff@nospam.com>]

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

-- 
Bryan Parkoff

"Hans Otten" <nobody@yahoo.com> wrote in message
WTHLQOo1moGxzuVUWVkwhcjBhdQE@4ax.com">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