[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: AppleColor Composite Monitors discussion
MdntTrain wrote:
David, Ferdinand, Michael...
Thanks -- the key I was missing (and now so obvious at that) was just
to display alternating lines. I should have known this as Michael
and I have been discussing TV Lines quite a bit off-group. And the
alternating lines ties in directly to bandwidth being half of dot
clock. These analog concepts are sinking in -- slowly.
The reason I'm interested in adding Y/C inputs to the AppleColor is
because I believe I'm just about done converting my IIgs to output Y/
C... using just a few added components to the mobo and putting out the
extra signal on unused pins of the DB-15 RGB port.
That's a cool mod!
Note, however, that a Y/C approach still leaves you with low-bandwidth
chroma, which means that single-pixel vertical details that have the
same luminance but differ only in chroma will not be well resolved.
For example, an 80-column display with blue background and green text
of the same luminance would be poorly resolved.
Another symptom of the same problem is that fine vertical details on
any background will lose chroma saturation.
An excellent demonstration of this is the "scrolling into infinity"
text at the start of Star Wars episodes--if a chroma/luma connection
between a DVD player and a TV is used (like S-Video), the wide letters
in the foreground text will be brilliant yellow, but as they scroll
into the "distance" and their vertical features become narrow, they
become increasingly washed out, until they are almost completely
desaturated.
Component video or RGB does not have this problem, of course, since
it is not bandwidth-limited.
-michael
NadaPong: Network game demo for Apple II computers!
Home page: http://members.aol.com/MJMahon/
"The wastebasket is our most important design
tool--and it's seriously underused."