IN 1978, THE WEST MERCIA FORCE DECIDED TO PURCHASE THE SERVICES OF A COMPUTER WHICH WOULD INITIALLY POWER A RESOURCE AVAILABILITY SYSTEM THAT WOULD BE CAPABLE OF CONSIDERABLE EXPANSION. THE DATA GENERAL NOVA 3/12 COMPUTER WAS SELECTED. TYPICAL FEATURES INCLUDE THE DISPLAY OF INFORMATION ON THE STATUS, LOCATION, AND CREWING OF DIFFERING TYPES OF POLICE VEHICLES. LESS TYPICAL IS ITS CAPABILITY OF INDICATING ALL DIVISIONAL RESOURCES, INCLUDING FOOT PATROL OFFICERS, WHOSE ACTIVITIES ARE UPDATED MANUALLY FROM REMOTE VISUAL DISPLAY UNITS IN DIVISION OFFICES. PERHAPS THE MOST IMPORTANT INNOVATION IS THE PROVISION OF 1,000 PAGES OF FREE TEXT, WITH 200 PAGES OF INDEX ACCESSIBLE FROM BOTH HEADQUARTERS AND DIVISIONAL DISPLAY UNITS. THIS ALLOWS FOR EXPERIMENTATION, DIVISIONAL INITIATIVE, AND PROVISION FOR ADDITIONAL SERVICE IN RELATION TO TEXT TRANSFER BETWEEN DISPLAY UNITS AT A LATER STAGE WHEN AN ADDITIONAL 2,000 PAGES WILL BE PROVIDED. THE SECOND STAGE OF EXPANSION INCLUDES THE LINKING OF THE DEPARTMENT'S COMPUTER TO THE POLICE NATIONAL COMPUTER TO AID IN ACCESS TO CRIMINAL INFORMATION. ALSO INCLUDED IN THE SECOND STAGE IS THE DEVELOPMENT OF PERSONNEL RECORDS FOR A MAXIMUM OF 3,000 PERSONS. A THIRD-STAGE EXPANSION WILL INVOLVE THE ADDITION OF A CONVICTIONS AND FIREARMS FILE FOR 200,000 CRIMINAL RECORDS AND OVER 40,000 SHOTGUN AND FIREARMS CERTIFICATES. THE PLANNED, PHASED DEVELOPMENT OF THE SYSTEM IS HELPFUL IN SPREADING OUT COSTS, TRAINING OPERATORS FOR THE SYSTEM, AND DEVELOPING THE EFFICIENCY AND EFFECTIVENESS OF EACH APPLICATION BEFORE UNDERTAKING ADDITIONAL OPERATIONS. GRAPHS ARE PROVIDED. (RCB)