I'm not sure I understood correctly what you mean by "doesn't recognize". Please add a forum reply here that provides a more detailed description to help me to understand it.
That indicates everything is fine. The fact that you get this indicates that you were able to select the port from the Tools > Port menu.
Regarding the "Unknown board", this is normal and expected. The ports of some Arduino boards have unique properties that allow the IDE to identify the specific board that produced that port. Other boards do not produce such properties, so the IDE is not able to definitively identify the board. The Diecilima falls into the latter category. This board uses a general purpose FTDI FT232R USB chip. Since many different boards use this chip, Arduino IDE has no way of knowing which board is on the other end of that FT232R.
But this is not a problem. The board identification is only a convenience feature. You can always manually select the board and port in Arduino IDE even if the IDE is not able to identify the port as that board.
This feature can only be used with the specific boards that have a supplemental module which requires firmware updates:
The Diecilima does not have any supplemental modules so the feature is completely irrelevant for this board.
I'm going to ask you to post the full verbose output from an upload attempt.
This procedure is not intended to solve the problem. The purpose is to gather more information.
Please do this:
Select File > Preferences... (or Arduino IDE > Settings... for macOS users) from the Arduino IDE menus.
The "Preferences" dialog will open.
Uncheck the box next to Show verbose output during: ☑ compilation in the "Preferences" dialog.
Check the box next to Show verbose output during: ☐ upload.
Click the "OK" button.
Attempt an upload, as you did before.
Wait for the upload to fail.
You will see a "Upload error: ..." notification at the bottom right corner of the Arduino IDE window. Click the "COPY ERROR MESSAGES" button on that notification.
Open a forum reply here by clicking the "Reply" button.
Click the <CODE/> icon on the post composer toolbar.
This will add the forum's code block markup (```) to your reply to make sure the error messages are correctly formatted.
Press the Ctrl+V keyboard shortcut (Command+V for macOS users).
This will paste the error output from the upload into the code block.
Move the cursor outside of the code tags before you add any additional text to your reply.
Click the "Reply" button to post the output.
No need. It is installed automatically. Just select Tools > Board > Arduino Duemilanove or Diecimila from the Arduino IDE menus and you're all set!
First, thanks a lot for replying, and replying fast.
As for the points:
Board not recognized, I meant in the board info, the BN was indicated as "Unknown board". You answered that very clearly .
For the firmware updater, your explanation is as well, very clear.
As for the code compilation, it was compiling well so there is no change.
For the code downloading.....
Well, now it works. I am sure you get this often.
I am not sure if it is related but we had a power failure (very short) and my Mac went down. I reloaded and, well now it all works. I use the output 13 with the onboard LED for the very first test and all is well.
Again, thanks a lot. It is much appreciated.
Regards
This procedure is not intended to solve the problem. The purpose is to gather more information.