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.
It was developed for the same purpose as PAL, but uses a different (and many would argue inferior) mechanism to do so. R-Y and B-Y information is transmitted in alternate lines, and a video line store is used to combine the signals together. This means that the vertical colour resolution is halved relative to PAL and NTSC.
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.
American engineers have been known to claim that SECAM stood for "System Essentially Contrary to the American Method".
Unlike PAL or NTSC, analog SECAM television could not easily be edited in its native form: instead, post-production was done in PAL, and the result then trans-coded into SECAM at the point of transmission.
We need some explanation of how the 'memory' worked...
Done: will this do? -- The Anome