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Re: IIGS composite video->VCR



mjmahon@aol.com (Michael J. Mahon) wrote in message news:<20020901233627.25665.00000988@mb-md.aol.com>...

Yes, you are correct. Sorry about misreading your earlier post. Thanks.

Hal

> Hal Bouma replied:
> 
> >mjmahon@aol.com (Michael J. Mahon) wrote in message
> >news:<20020828205023.22191.00004908@mb-mv.aol.com>...
> >> Mitchell Spector replied:
> >> 
> >> >DoNOT@feed.the.trolls (SlickRBCD) wrote:
> >> >
>  <snip>
> >> >
> >> >>but why wouldn't the text screen work in color?
> >> >
> >> >    It's a feature, which unfortunately cannot be changed using the
> >> >Control Panel settings.
> >> 
> >> Since the bandwidth of the NTSC composite chroma signal is
> >> less than 2MHz, you couldn't even get 40 characters across the
> >> screen.  That's why the color burst is turned off in text mode.
> >> 
> >> If the burst is on, as with mixed text/graphics screens, the
> >> high dot bandwidth of the luminance signal aliases into myriad
> >> of fuzzy colors on a composite display, producing a colorful but
> >> very hard-to-read display.  It would be impossible to produce
> >> more than about 24 characters of any _particular_ color without
> >> a much more clever video generator (with two-pixel wide dots
> >> and anti-aliasing).
> >> 
> >> -michael
> >
> >Thats not totally true. Seven and a half years ago I made some video
> >tapes of the IIGS programs I had written for my resumes to get into
> >the game industry. (For some strange reason, nobody owned Apple IIGS
> >computers anymore. Don't ask me why! ;) The only way I could show them
> >my work was with video tapes. Of course, I had someone with expensive
> >video editing equipment help me but we were able to record 80 column
> >text after he made some adjustments. (I had written a text mode
> >basketball game.) We were also able to record my 3200 color demo as
> >well. But you are correct that the color text settings are not
> >applied. Black background with white text is all you get.
> >
> >Hal Bouma
> >Software Engineer @ High Voltage Software
> 
> That's what I meant when I said "if the burst is on".  If color burst is
> present, it signals the monitor that there is a chrominance subcarrier,
> and high frequency luminance (black & white) data will be interpreted
> as color information, blurring and distorting the text.  If the burst is
> off, the composite signal is interpreted as black & white, and the full
> bandwidth of the monitor is available for displaying data.  For NTSC,
> this is generally limited to 4.25MHz, so 80-column text will not be
> particularly sharp, but it _is_ possible to read it.  (Most 80-column
> monitors have a bandwidth of over 10MHz.)  If the color burst were
> on, the text would be virtually unreadable, unless the chrominance
> (saturation) was turned all the way down (to produce black & white).
> 
> -michael
> 
> Check out 8-bit Apple sound that will amaze you on my
> Home page:  http://members.aol.com/MJMahon/