I'm finding various characters using ろうじんご in various works, and I'm trying to understand what are its characteristics; for example, わし for "I", じゃ/じゃろ as sentence-ending, のう I think like a vocative/emphasis marker (like here).
I'm trying to understand what are its characteristics and/or to find sources about it, but as for now I didn't find anything besides questions about single words (like this about わし).
So I wanted to ask what are its characteristics (if it makes sense to cover the topic as an answer here), or does anyone know sources explaining it?