This Characteristic provides guidance for the development and installation of a new generation of Cockpit Voice Recorders (CVRs) using solid-state memory. This document supersedes the earlier ARINC Characteristic 557. ARINC Characteristic 757A is intended to coexist with ARINC Characteristic 757 CVR. Supplement 1 provides the following: " The CVR unit description was updated to clarify the differences in the equipment designed to ARINC 757A versus that designed to ARINC 757, i.e., data link and OMS interfaces are required for ARINC 757A compliance. " Material was added to maintain document alignment with ARINC 757 which has FDR capability. ARINC 757A recorders are not required to have FDR capability. " The time correlation requirement was revised to specify that the CVR should receive its time signal from the same source as the Flight Data Recorder (FDR). " The OMS interface was updated to describe the correct ARINC 429 Sign Status Matrix (SSM) encoding for new CVR designs.