Two reasons: 1) cost cheaper to build (less materials) 2) no geometry software - no royalty fee -Miles Raymond Guillaume Tollu wrote in message <74s38k$m0q$1@platane.wanadoo.fr>... >I 'd like to know the different specificities of the different calcs... >Why is the Ti89 cheaper ? > >-- >Guillaume Tollu >g.tollu@wanadoo.fr >http://perso.wanadoo.fr/g.tollu/home.htm