you know, here's another question, probably one i should have asked earlier:
what format is this code?

29100000000C00000081

i mean, what's this format or encoding called? it would be a lot easier to refer to and look up answers about it if i knew what to call it, but in all my searching and reading, i keep seeing types of codes and formats named, and i always look them up to discover these formats are something different than what i'm dealing with.

oh, and if you're wondering why i don't just teach my universal remote the codes, button by button, it's because the remote that came with my receiver won't talk to my universal remote. the universal remote doesn't think i'm pressing any keys on the remote i'm trying to teach it from. i suspect the marantz remote is RF. it works even when i point it at myself / the couch. ugh. a "nice feature" in the remote is thwarting my universal remote attempts. and i really don't want a more modern universal remote if i can avoid it. i like HARDWARE buttons whose locations my fingers memorize by feel, not touch screens i have to look at (:sigh: i miss the days of android phones with full qwerty keyboards, too)