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We should think ourselves lucky there are only three incompatible colour TV systems in use today. Colour television came about during the cold war, a period of relative peace and stability for all that, and the distribution of the  PAL, NTSC and SECAM systems throughout the world followed largely geopolitical lines. Until the late seventies it really didnít matter too much which colour TV system a country was using, or their immediate neighbours for that matter. Demand for television sets could normally be met by indigenous manufacturers, then came video recorders, television satellites and cheap travel then suddenly TV became a global medium, and standards began to matter.


Multi-standard operation came first to television, where itís a relatively simple matter build in adaptability to display 525 or 625-line pictures and switchable colour processing circuits but the really significant development was multi-standard video recorders and they followed quite quickly once the VHS format gained significant toeholds around the world during the early 1980s. The first generation of multi standard machines could record and replay PAL, NTSC or SECAM tapes, but not convert from one standard to another.


By the mid 1980s television manufacture had become a global business, dominated by the Japanese and there followed a rationalisation of designs and key colour processing mircrochips that varied only slightly from one TV market to another. This had an interesting side effect and some PAL VCRs -- notably machines made by Hitachi -- were capable of replaying a passable 525-line NTSC picture (in black and white) on a PAL TV because of the in-built flexibility in the VCR and TVs video processing circuitry. By 1989 Mitsubishi and Panasonic had figured out a few simple tweaks to make NTSC replay in colour and partial NTSC conversion quickly became a commonplace feature.


Initially it caused a bit of a stir, and major US movie distributors were concerned about the prospect of a damaging cross-Atlantic traffic in American films but it never happened. The same trick was also used on Laserdisc players, and a small but significant US import market in laserdiscs has developed and survives to this day.


The next major development was true digital standards conversion but to date only one VCR of note has come onto the market, the truly amazing Panasonic NV-W1 VCR which

can transcode video to or from any video standard, and the quality is excellent; good enough for numerous small businesses to have grown up around it, offering to convert home movies for people with friends or relative abroad. Unfortunately itís quite expensive at around #2000, and not very widely distributed, and can be difficult to find nowadays. Aiwa briefly launched a couple of low-cost VCRs with digital standards conversion two years ago but performance was poor, and they soon disappeared.


Little has changed since the Panasonic W1, though itís clear that the coming of digital video will simplify matters considerably. In theory any digitally encoded video recording, whether on tape or disc, can be replayed on any machine, anywhere in the world. The coded information -- basically numbers -- should be the same wherever the disc or tape is mastered, the conversion to local TV standards takes place inside the player or VCR. The reality is somewhat different, as we have already seen with some CDi releases; there are considerable variations in PAL and NTSC originated recordings that show up on replay. Some -- like reduced picture height -- are merely annoying, others like deliberately or accidentally introduced coding differences can make discs from one country unplayable in another. Weíve come a long way in twenty years, but not so far that we will be able to watch anything we like, unless the powers that be permit it.



Here in the UK we use the PAL colour TV system, and in particular the PAL-I standard, the ĎIí defining -- amongst other things -- the difference in frequency between the sound and vision signals when they are broadcast. A PAL TV picture is made up of 625 lines, with a field repetition rate of 50Hz (i.e. the picture is shown 50 times a second).  PAL stands for phase alternate line, which describes the way the system corrects errors that can occur during colour signal transmission and processing. The NTSC colour system is used in North America, the Philippines, Bahamas and  Japan. NTSC stands for National Television Standards Committee, (aka jokingly known as Never The Same Colour by witty TV engineers), the NTSC is the US body who regulate technical standards for broadcasting. An NTSC colour picture is made up of 525 lines, with a field repetition rate of 60Hz; this was the first colour TV system to go into commercial operation in the mid 1950s and is technically less refined than PAL, which was developed several years later in what used to be West Germany; recent improvements in colour processing circuitry have narrowed the quality gap. The third system is SECAM or Sequential Coleur aí Memoire, (sequential colour with memory), it is closely related to PAL (though sufficiently different so as not to infringe any patents), and is used in France and throughout much of what remains of the Soviet bloc. Like PAL the picture is made up of 625 lines, with a field repetition rate of 50Hz. 



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