 CSC personnel became increasingly convinced that CP/CMS was the correct architecture for S/360 time-sharing.In September 1966, CSC staff began the conversion of CP-40 and CMS to run on the S/360-67.CP-67 was a significant reimplementation of CP-40; Varian reports that the design was "generalized substantially, to allow a variable number of virtual machines, with larger virtual memories", that new data structures replaced "the control blocks describing the virtual machines [which] had been a hard-coded part of the nucleus", that CP-67 added "the concept of free storage, so that control blocks could be allocated dynamically", and that "the inter-module linkage was also reworked, and the code was made re-entrant."