I use the willem I got from
sivava. I burn 27c400s, 27c256s all the time and a few 27c800s now and then and it hasn't given any single problem to me yet, aside from some burning issues which I relate to dead\dying roms. Keep in mind that you also need the 16bit eprom adapter (to burn 40/42 pin roms like 27c400/27c800). I use an old laptop with win98se to burn the roms (my 'new' pc don't even have parallel and serial ports ... aargh).
