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



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In article <1148923814.027068.144070@u72g2000cwu.googlegroups.com>,
js@cimmeri.com <js@cimmeri.com> wrote:
>I'm getting reasonable text results on my Highway scan converter
>experiment, but the vga hgr graphic results are intolerable (to my
>eyes).. not so much because of the converter, but because of VGA high
>resolution / dot pitch and lack of dithering.   Seems the Apples must
>be kept in relative lo-res monitors.   I was suggesting that new lo-res
>RGB CRTs will need to be created in order for IIgs' to work RGB-style
>20 years from now.
>
>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 should produce clean 80-column text and monochrome graphics, as long
as you're just connecting the composite output from the II into the S-video
jack's Y input and leave the C input disconnected.

As a quick experiment, I tried plugging a IIGS into my HD LCD TV.  Instead
of running a cable from the composite output on the computer to a composite
input on the TV, I ran it from the composite output to the Y input on one of
the TV's component inputs.  The image wasn't 100% stable (there was some
flickering), but 80-column text was easily readable.  I suspect that a
CRT-based TV (SD or HD) with component input would work better.  A
higher-resolution LCD and/or one intended for computer use (which will have
a button to make graphics more stable for the currently-active mode) might
also work better.

It should be possible to make an adapter to convert the IIGS's RGB output to
component video that would be usable on a growing number of TVs.  Since no
scan doubling would be necessary, the design should be simpler and cheaper:
a handful of op-amps to convert from RGB to YPbPr, and something to mix the
composite sync provided on the GS's RGB port with the Y signal.  There are
even computer monitors with component input, so you could use one monitor
with your GS and your newer boxen.  (I saw a 21" widescreen Samsung at
Costco last week that would be a nice upgrade from what I have
now...somewhere near 1600x1000, with all the inputs you could possibly need:
DVI, VGA, component, S-video, and composite.)

  _/_
 / v \ Scott Alfter (remove the obvious to send mail)
(IIGS( http://alfter.us/            Top-posting!
 \_^_/ rm -rf /bin/laden            >What's the most annoying thing on Usenet?

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