Hi, i use the original r4 from r4ds.com the last update was 1.18 is this card obsolete? will i have buy a new card? or is it possible to convert this card into another version?
yes and no - the official firmware has stopped, however you can use ysmenu (based on the DSTT firmware) or you can patch most games, some will never run but most will. If you are looking to buy again the R4 is now the one to avoid 40 different cards all using similar names, most rarely updated!
"will i have buy a new card?" No, but you should if you want any chance of playing new games. "or is it possible to convert this card into another version? " No, not at all.