>Anyhoo, I'd just like to try this signal generation manually first,
>in
>black and white, pumping out the sync and levels myself. Only
>downside is the amount of misinformation on the internet. It would
>seem that some say the sync pulse is about -0.4v, blanking around 0v,
>black around 0.3v, and white at 1v. Other people say sync can be 0v,
>blanking/black 0.3v, and white 1v. I've also seen sync at 0,
>blanking
>0.3, black 0.4, white 1, etc etc. I mean, does it really matter that
>much? Could I get by with just using 0, 0.3, and 1? I really don't
>want to have to try and start getting a negative voltage if
>avoidable,
>since to be honest, I'm not entirely sure how I'd do it at the
>moment. Televisions seem like they're fairly lenient, and with all
>the methods out there I've seen, I would assume most/all of them
>work,
>albeit possibly with less quality in some respect.
You need to worry more about the relative voltages than the absolute DC levels, since the video signal will likely be AC-coupled eventually.
The standard video signal when I last worked in broadcasting was 1 volt peak-to-peak, divided (for historical reasons) into 140 "IRE units". If blanking level was considered to be 0 units, sync would be
-40 units, black 7.5 - 10 units, and peak white 100. An older standard was apparently 1.4 volts p-p, which would make 1 unit = .01 volt.
The actual peak-to-peak voltage you produce may not matter too much, depending on what you are doing with the signal. If you are just feeding a monitor, you can adjust the brightness and contrast to get a decent picture from a fairly wide range of signal voltages.