Alain, Bernd,

I am really glad to see a team now working on this topic, I am sure this will speed up things tremendously .

Regarding the trees:

Bernd you are right, it looks like that a tree structure is saved. The difference between the old models and the "newer" ones (since the Diablo) is as follows:

For the SFC you could enter the following:

1.e4 d5 2.e4xd5 Nf6 3.c4 e6 4.dxe6 Bxe6 5.Nf3 Qe7 6.Qe2 Nc6

as a first line. To add a varaition of this line you just have to take back lets say in this case 4 moves via the "Take Back" function on the computer and continue then with

5.d4 Bb4+ 6.Bd2 Bxd2+ etc...

I guess for the new ones (like Diablo, Saphhire, Star Sapphire) you have to do it with 2 complete lines:

1.e4 d5 2.e4xd5 Nf6 3.c4 e6 4.dxe6 Bxe6 5.Nf3 Qe7 6.Qe2 Nc6
1.e4 d5 2.e4xd5 Nf6 3.c4 e6 4.dxe6 Bxe6 5.d4 Bb4+ 6.Bd2 Bxd2+

Thats the difference, but it might be that the internal format for this is similar, means its both saved like a "tree".

best regards
Stefan