[Coco] Cheap CoCo monitor without converter

[Brett Gordon]

I was reading up on my new flat screen hdtv, and noticed something
interesting:  the YPBPR component inputs accepts 480i (AKA regular 15 khz
NTSC).   I did some looking up, and I  found a "relatively" simple circuit
that can convert RGB to YPBPR... its basically just a  bunch of summing
amplifiers.

http://www3.telus.net/narmi/yprpb-schem1.png
http://eabmobile.abime.net/showthread.php?s=e4fa05cce21382a1e5a581ff5c9ab925&p=642631#post642631

Does anybody know if the Coco's RGB port have positive or negative syncs?
>From the Coco schematics, the GIME's /hsnyc and /vsync lines are hooked into
inverters before they go off to the RGB port. But those same signals work
fine on my RBG studio monitor.  So maybe I'll hook the CoCo up to a
oscilloscope and see for sure.
I'm going to see if I can mangle up a composite Y/sync line from the CoCo's
Green and Sync signals and test to see if my tv can figure it out.  It'll be
monochrome, but would be a proof of concept.  I'll see if I can get a 80
column screen to look any good.

-- 
Brett M. Gordon,
beretta42 at gmail.com