Classroom Teacher Support System (CTSS) is a prototype system for computer-assisted construction and scoring of tests, using questions from a central data bank. The computer programs for CTSS were developed by International Business Machines Corporation for study in the Los Angeles City Unified School District in 1969 and 1970. In order to provide maximum service to teachers, CTSS coordinators act as an interface between teachers and the computer center and maintain the test item bank. The system design, files, computer runs, and backup and recovery procedures are described in detail. (PF)