[en] The flowsheet of electronic logic circuits for the RISK hybrid magnetic spectrometer used for studying rare hadron-hadron and hadron-nucleon interactions is described. The circuit specific feature is the use of an event preliminary selection unit (PSM) to which signals from the primary particle indentification detectors placed near the streamer chamber are transmitted. PSM is made in the CAMAC standard. The K500 seies ECL type integrated circuits are used. The PSM application helps to decrease the time of event complete identification and cable delays in channels of secondary particle detectors and to unify the event selection circuits in experiments with the RISK spectrometer