(TORTOS) An operating system developed from MVT at Health Sciences Computing, UCLA by Dr. Patrica Britt from the late 1960s to the mid 1970s. Dr. Britt was a senior scientist at IBM, who become the Assistant Director of HSCF. TORTOS pre-dated TSO and provided batch, real-time and time sharing on an IBM 360/91. (2004-07-02)