SECAM

SECAM (Sequential Couleur avec Mémoire) is an analog television system, using frequency modulation to encode chrominance information. It is so named because it uses memory to store lines of color information, in order to eliminate the color artifacts found on NTSC systems. In was developed for the same purpose as PAL, but uses a different (and many would argue inferior) mechanism to do so. It was introduced in France in 1967, where it is still used; it has also been adopted in many former French colonies, as well as parts of Eastern Europe (Bulgaria, Yugoslavia) and the former Soviet Union.

We need some explanation of how the 'memory' worked...