▁browser . ▁ ▁They ▁were ▁built ▁for ▁use ▁with ▁two ▁ 1 G ▁data - only ▁packet ▁switched ▁networks : ▁ ▁M ob ite x ▁and ▁Data TAC . ▁ ▁They ▁did ▁not ▁support ▁Java ▁without ▁the ▁use ▁of ▁a ▁Java ▁Virtual ▁Machine ▁add - on . ▁ ▁Mon och rome ▁Java - based ▁models ▁( 5 0 0 0 ▁and ▁ 6 0 0 0 ▁series ) ▁ ▁Most ▁of ▁these ▁models ▁were ▁the ▁first ▁Black Ber ry ▁models ▁that ▁had ▁a ▁built - in ▁mobile ▁phone , ▁were ▁the ▁first ▁models ▁that ▁n atively ▁ran ▁Java , ▁and ▁transm itted ▁data ▁over ▁the ▁normal ▁ 2 G ▁cell ular ▁network . ▁R IM ▁began ▁to ▁advert ise ▁these ▁devices ▁as ▁email - cap able ▁mobile ▁ph ones ▁rather ▁than ▁as ▁two - way ▁pag ers . ▁At ▁this ▁time , ▁the ▁primary ▁market ▁was ▁still ▁business es ▁rather ▁than ▁consum ers . ▁ ▁The ▁ 5 8 1 0 ▁was ▁released ▁on ▁March ▁ 4 , ▁ 2 0 0 2 . ▁An ▁aber r ation ▁in ▁this ▁list , ▁the ▁ 5 7 9 0 , ▁was ▁released ▁at ▁a ▁much ▁later ▁date ▁as ▁a ▁n iche ▁model ▁in ▁ 2 0 0 4 ▁after ▁many ▁color ▁Black Ber ry ▁models ▁were ▁out . ▁This ▁non - phone ▁Black Ber ry ▁was ▁made ▁available ▁due ▁to ▁the ▁demand ▁for ▁a ▁Java - based ▁model ▁that ▁could ▁run ▁on ▁the ▁M ob ite x ▁data - only ▁network . ▁The ▁