Hi, welcome to my little guide on TV compatibility. Feel free to ask any questions and I will answer them to the best of my ability

Introduction - Incompatibility

Buy a console from abroad and the chances are you won't be able to play it, straight from the box, in the UK. This incompatibility is the result of the different countries adopting different TV broadcast systems.

When these systems were adopted the only thing that was available on TV's was broadcasted programs. Broadcasted signals only carry over very limited distances. TV signals transmitted from the US couldn't be picked up by Europeans (this was before the advent of satellite broadcasts) and only in extremely exceptional atmospheric conditions could TV signals from France be picked up in mainland Britain.

This incompatibility began to matter when VCR's became popular. The pre-recorded VCR tapes purchased in the US couldn't be played back on European VCR's.
Incompatibility really became a problem to gamers with the launch of consoles, primarily in Japan but also in the US

Getting Technical

The world divides into two main standards, North America/Japan and Europe.

In North America/Japan, TV pictures are built from 525 lines displayed at a frame rate of 30 a second - or 30hz.

In Europe, TV pictures are built from 625 lines displayed at a frame rate of 25 a second - or 25hz.

Why were the display rates chosen?

The display rates were originally chosen to match mains supply frequencies, though that is no longer any connection between the two (some cities in Japan have 50hz mains whilst others have 60hz).

Mains voltages around the world are usually 200-250v in the 50hz territories and 100-110v in the 60hz. This means that any console (or other electrical equipment) imported from the US or Japan needs to be used with an external transformer which can lower the voltage. These transformers are usually referred to as Stepdown Converters.

Wait a minute. Some of that doesn't make sense. How can the TV display rate in the US be chosen to coincide with the mains voltage if it only displays 30 frames per second - or 30hz - when the mains voltage is 60hz?

The answer to this is that both territories use interlacing, to avoid the flicker that is obvious on any picture displayed at 25 or 30hz.

Half the lines of the picture (the even numbers) are displayed as one field and then the other half (odd numbers) are displayed as a 2nd field. Together the two fields interlace, like a closed zipper, to give a full frame. Persistence of vision, plus the after-glow characteristics of the phosphors on the TV screen, makes interlacing appear seamless.

So it's correct to refer to a 525 line system as either 30hz or 60hz, and a 625 line system as either 25hz or 50hz. Its common practise to refer to them as 60hz and 50hz accordingly though.

Are there any disadvantages to this interlacing?

There is one main disadvantage. The horizontal edge lines in the picture flicker as they are moved slightly up or down with each field change.

This can be improved though by refreshing the picture at a higher rate or by scanning sequentially by combining the two fields into full frames before displaying them.
This is why 100hz TV's are sometimes called flicker-free.

OK, you've explained where 50/60hz come from. But the box my console came in says NTSC not 60hz. What does that mean?

The main 525 line/60hz system is called NTSC, after the National Television System Committee. It was adopted in the United States in 1953. Japan also adopted the NTSC system due to the close ties between America and Japan after the Second World War. Japans economy was destabilized during the 2nd World War and America helped to rebuild the Japanese industry and provided substantial financial aid.

So what does PAL mean then?

Most of Europe (which is the main 625 line/50 hz territory) adopted PAL, which stands for Phase Aternate Line. It was developed by Telefunken in Germany. The BBC was the first in Europe to start a PAL coloured service in 1967.

Isn't there another one? SECAM I think it's called.

France adopted a different 625 line/50hz system. It was called SECAM, Sequential Colour with Memory. The Eastern Bloc followed suit.

France did this to protect its own TV production industry, and the Eastern Bloc did it to try and stop its citizens watching foreign TV.

Most TV sets in France are now dual PAL/SECAM and since the fall of communism in the Eastern Bloc most of the former communist countries have been switching to PAL.

So PAL and NTSC are the two main formats in the world today.

Ok, you have explained all that so let's get down to the important stuff. Why are there big black borders on my PAL games?

Not all the lines of the TV picture are used to display a visible image. In PAL regions only 576 lines are active. The rest form the Vertical Banking Interval or VBI for short, and define unseen black borders at the top and bottom of the picture. These VBI lines can be used to carry digital code, such as teletext.
The NTSC system has 480 active lines.

Different types of Connection

Where incompatibility really matters is when dealing with the many different kinds of audio/visual connections on TV sets.

• RF

The basic type of connection for PAL consoles is the RF connector, also known as the aerial connection.

A modulator is used to connect the console to the RF connection on the TV. An RF connection is a composite signal which is coded according to the country of sale, for either the NTSC or PAL system, and modulated on either a VHF or UHF radio frequency carrier. An RF connection is strictly mono, so you lose the benefits of today's consoles audio capabilities.

Some NTSC consoles have been modified to play through the RF connector to a PAL TV. The frequency that an NTSC signal is broadcasted is 3.85MHz, whereas the PAL frequency is 4.43MHz. The console is modified to transmit the higher frequency.
This modified signal is sometimes called Quasi PAL because the line and frame rate remain at NTSC standard (525/60hz).

The picture synchronization in most modern PAL TV's has enough latitude to cope with either a 525/60hz signal or a 625/50hz signal. If the TV can cope with the NTSC signal then the picture will fill the entire PAL screen. If it can't, the picture will either be letterboxed (borders top and bottom) or in the worst instances the picture will roll (scroll continuously from bottom to the top of the screen)

• RCA Jacks or Composite Connection

Most of the recent consoles I have bought on import have shipped with a composite connection as standard. An RCA lead connects to your TV via three phono plugs. The connection is normally situated at the front of your TV. The three phono plugs are normally yellow, white and red. The yellow plug transmits the video signal and the white and red are left and right audio.

The composite is exactly the same as an RF signal except its not modulated and its also in stereo. On some older PAL TV's the composite signal from an NTSC console will appear in black and white. This is because a true NTSC signal is being sent through the RCA jack and the TV isn't able to decode it properly.

• Composite Scart

Exactly the same as the RCA jacks but this time it connects to the TV via the scart socket on the rear of the TV.

Same problems apply as the RCA jacks.

• S-Video

The s-video connection is a mixed feed of luminance and chrominance signal. It's a video only signal but the s-video cable normally comes with left and right audio phono plugs connected.

Same problems apply as the RCA jacks.

• RGB Scart

The RGB feed provides four signals, one for the red content of the picture, one for the green and one for the blue (hence the name RGB). The fourth signal is a composite sync signal which combines horizontal and vertical pulse information so that it behaves like a TV picture with no picture content.

RGB scart is the best way to connect consoles to your TV in the UK. The RGB signal is in its purest, uncoded form. The differences between PAL and NTSC colour coding are completely bypassed.

Hold on! I used RGB scart on my old TV and the picture from my imported console was in black and white

Some early TV sets with scart sockets didn't have the RGB pins connected, so the RGB scart lead acted as a composite scart. Most modern TV's now have the RGB properly connected.

On TV's with more than one scart socket you will find that only one of the scart sockets is RGB compatible. On the TV's I have owned it's normally Scart 1 but it's just a case of trail and error.

Most modern TV's have sufficient flexibility in their synchronization circuits to lock onto a 50hz or 60hz signal.

As I have already said RGB scart is the best method of connecting imported consoles to a TV in the UK. The full screen 60hz display that results is vastly superior to the letterboxed 50hz display.

Graphics are bigger and clearer, and most importantly, the games run at the speed they were actually designed to, making them faster and harder in the process.

Not all consoles are RGB compatible though. For some strange reason Nintendo decided to make the N64 non-RGB. It was easily correctable by a simple modification though. To Nintendo's infinite wisdom they have decided to make the Gamecube non-RGB as well.

So PAL consoles aren't worth bothering with then?

There are ways around the PAL problems.

The Playstation was able to transmit a 50 or 60hz signal depending on the region of the software. Play an imported NTSC game on a PAL Playstation (modified to remove the territorial lockout) and it would run in full screen 60hz. An RGB scart was needed to display the picture in full colour.

Atari tried to combat the problem by discouraging letterboxing in titles for the Atari Jaguar. They claimed that their non-territorial games could detect whether they were being played on a NTSC or PAL system and thus play at the optimised speed and screen size.

Optimised? Does this mean that you can get a full screen 50hz picture? That sounds promising

Optimised 50hz still hinders things though. The drop to 50hz from 60hz results in a 17% speed drop. Developers could always turn up the game speed in their code to counter this but that is the exception rather than the rule.

Also, non-letterboxed 50hz means an increased number of lines to display (625 instead of 525) so there's a greater drain on the processor, which could result in slowing the games down even further.

So, yet again, PAL consoles aren't worth bothering with are they?

Remember I said that the Playstation could display a 50 or 60hz picture, regardless of whether it was a PAL or NTSC Playstation? Well it wouldn't have been too much of a leap for Sony to ask developers to include a 60hz option in some games, or to even have released a European 60hz version of some of Sony's own big selling games (Gran Turismo would have been a perfect example)

Sega, with the Dreamcast, was for me the champion of the European gamer in some aspects.

It was another console capable of transmitting a 50 or 60hz signal, but this time Sega took full advantage of it. The majority of Sega published PAL games featured a 60hz option, and Sega also asked all 3rd party developers to try and include a 60hz option into their games as well.

The Playstation2 is another case of Sony manufacturing a console capable of transmitting 50 or 60hz signals.

Up to now though they haven't taken advantage of this. A 60hz option in most PAL PS2 games is virtually non-existent, in fact some of the most recent PS2 games have been very poor 50hz conversions with very prominent letterboxing (for example Onimusha). At this moment in time the PS2 gamer is advised to go the NTSC importing route to appreciate full screen 60hz gaming.

Nintendo has hardly ever been a friend to the PAL gamer in terms of 50hz conversions.

Some of the early N64 titles were exceptionally shoddy 50hz conversions - for example Lylat Wars (starfox 64) with its huge borders. Hopefully with Nintendo's change from a cartridge to a proprietary cd format, with its larger data storage, might be cause for a big improvement with the Gamecube - that's if it can transmit a 60hz signal as well as a 50hz.

With the Xbox still some months away from a PAL release no details have been issued on whether they will implement a 60hz option for PAL gamers. We can but live in hope.