Thank you! I'd definitely like to make it so people can choose their own chime, patch the firmware update, run it, and have a new chime

Thanks to mcdermd, I now have two G3 logic boards to try to patch with a custom chime! I'm thinking that I should be able to test this out fairly soon...thank you so much, mcdermd!

The two logic boards have Sharp flash chips as opposed to mine, which has a Micron flash chip. So Apple definitely used different brands throughout the production. That explains without a doubt why the firmware update code has so many cases for different chips. Anyway, just another little tidbit as I figure this stuff out!