Git line endings

turns out it's doing exactly what it's supposed to do: translate to your local machine based on your machine's configuration.
Yes, I got that. But is it not doing that based on the .gitattributes of the fileset, not the machine configuration?

My scenario is
1) my new shop starts with a sourceforge fileset: unix endings.
2) I merge my mods in from the current production shop, taking care to convert these to unix endings.
3) over time, new things appear in Github v158 that I may want to merge in too: but these checkout automatically converted to Windows endings as per the .gitattributes "* text=auto" that is in the github fileset. So any file I want to merge, I'll have to convert manually.

So if I want to stop Git checkout converting the checkout to windows endings, I suppose I need to change the gitattributes "* text command....but if it is part of the fileset, how can I do that/override it?