After playing around with the B01 board I went back to look at the software. It turns out that I inadvertently downloaded and installed Jetpack 4.4 Developer Preview:

If you want to know more about this version of the Jetson Nano Developer Kit software, there is this:

https://forums.developer.nvidia.com/t/jetpack-4-4-developer-preview-l4t-r32-4-2-released/120592

The Developer Preview seems to have some of its own oddities. For example, I discovered that Python’s pip wasn’t installed. Pip’s needed to install a set of tools I’ll talk about next. But in the mean time, you need to follow these directions to install pip for Python3:

https://pip.pypa.io/en/stable/installing/

Once pip is installed you need it to install a set of Python-based tools known as jetson_stats. Included in that collection is jtop. You can follow the directions on the GitHub repository here:

https://github.com/rbonghi/jetson_stats/wiki

Note that the latest Jetson Nano Developer Kit is still based on Ubuntu 18.04.4. I’ve looked around and it would appear that migrating to Ubuntu 20.04, the current LTS, is some ways off. Which for me isn’t a problem as there’s plenty to work with as is.