This firmware seems to read faster and with less speed drops than the 48125w fw, vs02-vs06. It writes the same as the vs06 fw. My drive is an original 40125s.
Thanks go to Fatass & Dyzan, I guess !
For my Ricoh 12x media, I still get better results with WS09 than 1S01
And the real adress is:
1S01 appears to be a newer code base (021B vs 020B).