The Calculation of Nucleon Cascades in Nuclei by the Monte-Carlo Method.- Beam Behavior in a Sector Cyclotron.- 1. Harmonic Analysis of the Magnetic Field.- 2. Determination of Equilibrium Orbits.- 3. Orbit Stability, Betatron Oscillations.- 4. Analysis of Vertical Motion.- 5. The Calculation of Trajectories for Ion Drift in an Inhomogeneous Magnetic Field.- Literature Cited.- Vassal (Automatic Memory Allocation System).- 1. Input Language for the Vassal Translator.- 2. Some Remarks on Programming in Vassal.- 3. Translator Operation.- 4. Rules for Pending Vassal Program.- Literature Cited.- Determination of Reactions Cross Sections from Counter-Telescope Data.- I. Relation Between the Output and the Cross Section.- 1. Formulation of Experiment. Definitions.- 2. Calculation of the Cross Section from the Output without Correction for Multiple Scattering.- 3. Multiple Scattering.- II. Calculation of the Output in the Case of the Compton Effect and the Photoproduction of Neutral Mesons on Hydrogen.- 1. Definitions and Additional Restrictions.- 2. Evaluation of the Multiple Integral.- 3. Analysis of the Output Integrand.- 4. Determination of the Range of Integration for the Entire Integrand.- III. Program for Calculations on the M-20 Computer.- 1. Description of Program.- 2. Program Checks.- 3. Conclusions.- Literature Cited.- Typical and Atypical Failures of the General-Purpose Computer M-20, Methods of Localization and Elimination.- I. Failure Detection from the Control Console.- 1. Tests and Test Problems.- 2. Fault Analysis in the Execution of Individual Instructions.- II. Failure Detection by Technical Means.- 1. Choice of Synchronization Method for the Localization of Intermittent Failures.- 2. Utilization of Auxiliary Circuits for the Localization of Transient Failures.- 3. Preventive Maintenance.- III. Typical Failures of the Basic Devices on M-20.- 1. Typical Failures of CM and Their Elimination.- 2. Typical Failures in Backup Storage (Magnetic Drums and Tapes) lS2