I am trying to load a code on an old arduino nano, so I should select Tools -> Processor -> Old Bootloader.
The point is, this rumor is gone! I can't find it anymore on any version of the Arduino IDE.
I have tried to download multiple versions with no success.
Some advice??
Do you have Tools > Board > Arduino AVR Boards > Arduino Nano selected? The Tools > Processor > ATmega328P (Old Bootloader) menu item only appears once you have selected the Nano board.
If so, and you still don't see a Tools > Processor > ATmega328P (Old Bootloader) menu item, this means you're using an outdated version of the Arduino AVR Boards platform (in which case Tools > Processor > ATmega328P is the equivalent of the "old bootloader" setting and what you're really missing is the new bootloader option). The boards platforms versions can be independent from the Arduino IDE version, meaning you can have an outdated Arduino AVR Boards even with an up to date IDE. You can update the Arduino AVR Boards platform by following these instructions:
From the menus, select Tools > Board > Boards Manager
Wait for the update to finish.
Scroll down through the list of boards platforms until you see "Arduino AVR Boards". Click on it.
Click the "Update" button.
Wait for the update to finish.
Click the "Close" button.
You should now have a Tools > Processor > ATmega328P (Old Bootloader) menu item.
No need for apologies. This is confusing stuff and Arduino is all about learning and sharing knowledge. I'm just glad if I was able to be of assistance. Enjoy!
Per