Using custom cores won't recognize multiple configurations

I'm trying to customize the core to a sibling folder to the genuine core folder and be able to select the correct board from the "boards" menu in the 1.6.5 IDE.

I'll assume you'll be familiar with this process and leave out the play-by-play.

I successfully got it to work without any difficulty. As I understand it, the key to making this work is editing only two lines .name and .build.core. So, I copied and pasted the Mega256 parameters in the boards.txt file and altered the two lines. Booting the IDE and checking the "boards" menu, my new board name is there. The problem is, the old name is NOT there. Is it no longer possible to have dual core configurations for the same physical board?

If it's not clear what I'm talking about, this link should explain it.

Custom Arduino Cores

Post the two entries (original and modified) from your boards.txt file

I suspect that both entries have the same "internal name" - the letters before the first dot on every line, so the second config block overwrites the first.

if I have

uno.name="Arduino Uno"

and then later in the file

uno.name="Arduino Uno (256 serial buffer)"

the second one will overwrite the first, because now you've set uno.name to something different. You need to have something like uno256.name=... (and the same thing for each line of that entry).

Very easy to screw this up when copy/pasting.

Very good. That's the part I missed. Thank you