Re: Let's pay a developer to make a VGA output card

Alex Freed wrote:
js@xxxxxxxxxxx wrote:

I don't know if S-video can produce legible 80col text, but perhaps
another way to go is to figure out how to perform surgery on the II's
to produce s-video composite output.


S-video is only different from composit video in one respect - the color
information comes on a different wire than the luminance. The way video
is generated in apple 2, they are inherently mixed. So it doesn't matter
much if you try to separate them at the computer side rather than inside
the TV. A modern TV will likely do a better job with a comb filter.

There is one difference--the S-Video luminance signal is not necessarily
assumed to be band-limited, and it *is* assumed to not have a chroma
subcarrier present. So it is often processed with wideband video
processing, and could deliver much better than 3MHz video bandwidth
for good 80-column text. It all depends on the monitor and its video
processing.

It is pretty easy to split composite for an S-Video input. There
are adapters available in stores and construction articles on the web.

-michael

Parallel computing for 8-bit Apple II's!
Home page: http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it is seriously underused."
.

Relevant Pages

  • SCART to S-video/Composite
    ... opted for S-video, knowing it's better than composite video. ... The VHS recorder has a SCART connector, so I've used a SCART adapter ...
    (sci.electronics.design)
  • Re: Please review my proposed Shuttle Media Center PC spec
    ... > composite syncs, although I wonder whether TVTool (I use that on my Dell ... I know that my DIVX video is improved tenfold when processed ... Without TVTool the s-video ...
    (microsoft.public.windows.mediacenter)
  • Re: Recording from a VCR through Windows Vista Media center
    ... You can not convert 2 wire composite video to 4 wire S-Video video the adapter you have only goes from S-Video to composite and not also from composite to S-Video. ... A composite video connector has a Yellow RCA connector and Stereo cables have Red and White RCA connectors. ...
    (microsoft.public.windows.mediacenter)
  • Re: Lets pay a developer to make a VGA output card
    ... The Apple II/+ was designed for composite or RF, ... eventual composite video output. ... mods to allow this same chip provide S-Video! ...
    (comp.sys.apple2)
  • Re: IIgs video problem
    ... The first has problems on the composite out. ... The sync is mixed into the video with a transistor driven by a gate. ... The transistor may be weak or the gate output substandard--or a resistor ... parallel computing for Apple II computers! ...
    (comp.sys.apple2)