While Retroarch does support rewinding, I could not get it to work for me for SegaCD games.
I have a Raspberry Pi 2 running Retropie 3.2.1, and enabling rewind would cause the emulator to instantly quit (crash?) after trying to load a game. The strange part was that it was not logging errors or crashes.
I turned on the most verbose logging options possible and the log files would indicate that it was preparing the rewind buffer, and that was it – that was the last log entry. No crash message, no further log entries, and nothing in dmesg either. There might be a separate log file somewhere (system log file? The logs for “runcommand”?) that detail the crash, but retroarch’s own log files weren’t outputting anything to indicate the root of the problem.
I tried tweaking the buffer sizes down to 20MB and still nothing. I need to experiment more, but in my current experience rewinding is not functional, and may never be functional given the lower amount of RAM that the RPi has compared to something like a desktop or HTPC.
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