THE FOLLOWING PROGRAM IS SUBMITTED BY: HARRY ATHERTON UNIVERSITY OF CINCINNATI MEDICAL CENTER DEPARTMENT OF PEDIATRICS, ML 541 231 BETHESDA AVE. CINCINNATI, OHIO 45267 PHONE (513) 872-5341 THIS SUBMISSSION CONTAINS SEMAPHORE DIRECTIVES FOR THE RSX-11M AND RSX-11M-PLUS EXECUTIVE. THE MATERIAL FOR RSX-11M-PLUS V2.0 IS IN [364,22]; THE MATERIAL FOR RSX-11M V4.0 IS IN [364,24]. THESE DIRECTIVES ARE USEFUL FOR SOLVING PROBLEMS OF CONCURRENT ACCESS OF MULTIPLE TASKS TO DATA STRUCTURES (OR ANYTHING ELSE). A DESCRIPTION OF THE DIRECTIVES AND INFORMATION FOR ADDING THEM DURING A SYSGEN ARE GIVEN IN SEMINFO.RNO. INFORMATION ON SEMAPHORES IS GIVEN IN THE PAPER "IMPLEMENTATION AND APPLICATION OF SEMAPHORES IN RSX-11M" PRESENTED AT THE FALL 1979 DECUS. REPRINTS ARE AVAILABLE FROM THE ABOVE ADDRESS.