sync on green to horizontal and vertical wiring seperator.

The place to look for the signals isn't in the monitor, but on the video generation circuitry. If there's a horizontal and vertical sync available anywhere in your video generation circuitry, you'll want to measure their durations and frequencies, as well as polarity. There may not be separate sync at all if it's generated as composite sync in some specialized IC. That's adequate for sync-on green, but if you want to attach a PC monitor you'll have to go to some trouble. You can generate the negative-going sync most easily by using a negative supply. If you use a current mirror controlled current sink that pulls the 75-ohm resistance to ground down by half a volt or maybe 3/4 volt, and then use a diff-amp made from a couple of transistors to switch the sync on and off, you can get negative sync from one transistor or the other's collector. Clamp the base of one (depending on the polarity of your sync) to gnd with a schottky with about 0.3 volts forward voltage, and limit the current at that base with yet another transistor also controlled by the current mirror, such that the voltage at the base of these transistors ranges from as high as the clamp will allow, to about the same amount below gnd, by limiting the current from the sync signal, with a resistor, typically 1K-ohms. attach the appropriate transistor in the diff-amp to the green video. Set the current in the transistor that sinks the current from the diff-amp to such that the sync voltage is about half a volt below ground. If you need more details, let me know. I normally use VERY fast transistors in a 5-transistor array (CA3127/3227) to do all this. A CA3183 would probably also do the job, but I like the sharp edges the UHF array produces. Dick ----- Original Message ----- From: <jpero(a)sympatico.ca> To: <classiccmp(a)classiccmp.org> Sent: Sunday, June 10, 2001 3:38 PM Subject: sync on green to horizontal and vertical wiring seperator.