▁It ▁was ▁specifically ▁designed ▁to ▁allow ▁very ▁efficient ▁handling ▁of ▁mess aging ▁where ▁the ▁number ▁of ▁messages ▁waiting ▁for ▁processing ▁could ▁be ▁almost ▁un limited . ▁ ▁It ▁is ▁also ▁aim ed ▁at ▁reducing ▁one ▁of ▁the ▁primary ▁costs ▁of ▁mess aging , ▁namely ▁having ▁to ▁constantly ▁move ▁messages ▁around ▁in ▁memory . ▁ ▁Even ▁moving ▁them ▁from ▁the ▁communication ▁manager ▁to ▁the ▁message ▁queue ▁sub system ▁to ▁the ▁processing ▁program ▁is ▁elimin ated . ▁ ▁Instead ▁each ▁message ▁is ▁placed ▁in ▁a ▁small ▁bank ▁of ▁its ▁own . ▁ ▁Inst ru ctions ▁allow ▁placing ▁the ▁bank ▁descript ors ▁of ▁these ▁banks ▁in ▁a ▁queue ▁and ▁removing ▁them ▁from ▁a ▁queue . ▁ ▁When ▁a ▁message ▁is ▁placed ▁in ▁a ▁queue , ▁the ▁sending ▁program ▁or ▁sub system ▁no ▁longer ▁has ▁any ▁access ▁to ▁it . ▁ ▁That ▁bank ▁is ▁removed ▁from ▁its ▁address ▁space . ▁ ▁When ▁a ▁message ▁is ▁retrieved ▁from ▁a ▁queue , ▁the ▁bank ▁becomes ▁part ▁of ▁the ▁receiver ' s ▁address ▁space . ▁ ▁The ▁que uing ▁instructions ▁also ▁provide ▁activity ▁synchron ization ▁functions ▁( e . g ., ▁wait ▁for ▁a ▁message ). ▁ ▁Only ▁" pointer s " ▁are ▁moved ▁and ▁they ▁are ▁moved ▁in ▁a ▁way ▁that ▁ens ures ▁security ▁and ▁integrity . ▁ ▁Once ▁moved , ▁the ▁data ▁in ▁the ▁message ▁is ▁only ▁visible ▁to ▁the ▁recip ient . ▁ ▁I / O ▁Process ors ▁▁ ▁All ▁I / O ▁on ▁ 2 2 0 0 ▁Series ▁systems ▁is ▁handled ▁by ▁I / O