Thx a lot for all this!
i do understand that image couldn't be loaded at boot ...
The reason i wish to try this was that i sometimes need tools to access broken windows or linux. Thus i was looking for any kind of rescue-linux, and thougt knoppix could do that.
I think RUNT should be better for this kind of work : with floppy disk one can boot usb-key and run runt with many tools to access and repear broken systems. as there is no graphical tools, it is easier to load within 64mo ram.

Any way i thank you for the time you gave me about this question.

and ... sorry for my very poor english