So, i searched back in the archives and found one short thread on this topic. There was one hint that the aty128fb in kernel 2.2.x does not accept cmdline options. So I compiled kernel 2.4.4 and indeed the cmdline options work there fine ...
Then i went back to 2.2.19 and supprise: with the vesafb the framebuffer and the console seem to work absolutely fine. Except for the fact that "it does not support changing the video mode" latter with fbset but i think i can live with that. Imre