Intrigued..

[FONT="Comic Sans MS"]Please could someone tell me how a dvd player or recorder remembers the film you watched three weeks ago and stopped it in the middle. Since then you have watched three more films all the way through listen to 2 scad's and watched wallet and gromit twice. How dose it remember that one film and start exactly where you left it?.[/FONT]

[Paul O]

I think some DVD players have memories for about 30 or so discs, so when you put it back in it resumes from where you left off.

I suspose the function is to make it similar to a video player, but I found it a bit annoying on my last player!

[swapped]

My guess would be that as each DVD is divided into a variable number of chapters, and each chapter is of a variable length, you would have to be unlucky to find two different DVDs that matched on both counts, and that's where the unique identification of recently inserted discs becomes possible.

The first thing a DVD player does when it fires up is to check those numbers, and if it 'recognises' the disc inserted, and has a record of you stopping playback part way through the last time it was inserted, that's when the player can offer to resume playback at the part-way point.

None of this takes any calculation / processing / time on the players part, and only a tiny amount of memory to store.

Arnt you all a clever bunch !!!!!!!! thanks for that .. i had to ask...