Scratch

Folbo wrote:

I am teaching scratch with 25 students on literally identical machines (citrix virtual W7 clients). We are having a go at PacMan.

24 computers work fine.

One computer gives jerky motion even from the most simple of scripts such as

when gf clicked
forever if ( color (3) is touching (6) ? )
    move (4) steps
end

where the sprite contains a blob of colour 3, and the background is colour 6 (I have no idea what the actual colour values!).

any idea where I should look?

Thanks.

If 24 other computers work perfectly, then that's a strong indicator that either the problem lies with the computer, or something went wrong when you downloaded Scratch. If programs other than Scratch [on that computer] are lagging, then the problem is probably with your computer, but if other programs work smoothly, then you might want to try reinstalling Scratch. Other than that, if you have an questions, the scratch forums are a really great place to ask them.

I hope that this answers your question!