That 12v line is indeed correct
High is 9.5v to 12v.
http://www.js-technology.com/technical/ ... nector.pdf
Basically all it does is to force a 4:3 mode. On some current televisions you can't switch between composite and RGB via the handset, and that's what pin-16 is for.
I also wouldn't put resistors on the RGB lines either. You're *supposed* to as dictated by the purists, bringing the ST's 1v signals down to 0.7v. But in experience it just creates ghosting around text and alike. On older televisions it does not do this, but certainly on the 3 modern LCDs I've tried it does. Removing the resistors limits this. Just turn the brightness down a bit to compensate.
There are some modern televisions out there where the ST doesn't work at all, along with other computers of the age. The sync signals that they generate are not *digitally* perfect as it were. On an older analogue electronics (not digital chips doing the signal processing) style television this isn't a problem. Modern consoles and alike output completely standard without tolerance signals, they're standard A1 perfect.
The analagy I've always used is like the difference between an audio signal going to your headphones, and the digital output dat stream from a CD player. Today's equipment is almost totally intolerant of variations. Which is why the consoles output signals are generated precisely by specialist chips, where as the older computers go through a few resistors and capacitors via some old chips that were cheap at the time yet did the job.