I finally got my Newton 2100 and my Pismo to communicate. After trying multiple times I finally decided to read the directions. Yep, I had to read directions, step by step. I downloaded the Newton Connection software for OS X, and hooked up my Keyspan USB to Serial adapter, and my Serial Adapter for my Newton and followed the instructions that came with the NCX software.
The only thing I did differently was the terminal command for setting the BaudRate. I set it to 115200 as in the directions then read further that I would then need to install on my Newton a piece of software to up the Newton's BaudRate also. Well, there hangs the problem. Getting it onto the Newton is the issue now isn't it. So, I changed the BaudRate to 9600, which is acceptable to the 2100 settings already, and hit Return. Immediately the grayed out icons became bold, and the communication bar started to move. I'm doing my first backup to my Pismo now and the next step will be to download all the new software! Yippee!
If anyone wants the URL for the Newton Connection Utility for OS X, I think I found it following a RetroMacCast Users webpage link. Here it is: http://homepage.mac.com/simonbell/connection/
Thanks Simon Bell! You Rock!