Does anyone have any information relating to the differences and problems encounted by creating games for NTSC and PAL sets. Anyone got links to informatino about this subject

PAL runs at 29.970 fps and NTSC at 35 or so I believe.
The resolution also differs.
Those are the main differences.

does this in someway affect the timing of the game, meaning slight different coding for timings and phyicis etc

I admit that I haven''t done any console development yet but I don''t see how this would cause any problems. You can use a simple frametimer to solve the frequency problem.

When I was working on the Amiga computer, PAL machines had a low-res mode of 320x256 at 50hz, and NTSC had a low-res mode of 320x200 at 60hz.

Probably the best way is to code your game to be frame rate independant. You might want to look into using the system clock to time how long the last frame took, and use that to scale the physics for this frame. I think most games do this.

Hope that helps you.

- Peter
peter@digital-animations.com

Yes, the main differences are the height of the screen, and the VSync rate (PAL at 50Hz, NTSC at 60Hz).

A PAL screen has a slightly taller display, due to there being more lines in the display. The actual resolution for a particular system varies. If you develop a game for an NTSC television, then PAL users will have borders at the top and bottom of the display.

The 50/60Hz might also be a problem. If you can take the time between frames and use this then you should be ok, although normally this isn''t really desired as it might be easier/more efficient to code the game for a specific frame rate.
Also note, that the timings may affect other parts of the hardware as well, depending on the system.