Not exactly an easter egg, but if at some point you find you need to do a warm start [On]+[Symb] on the Prime, it will put the calculator in a mode where you can press a key sequence to see a quick pop up banner at the bottom of the display that says Pedagoguery Software Inc www.peda.com.


When the warm start completes, my calculator defaults to the "Advanced Graphing" environment (i.e. a window with "Advanced Graphing" in the title bar).

Press the [Plot] key, which should generate the No open sentences checked warning message.

When you press the [Esc] key, the screen changes to an x y grid and the Pedagoguery Software Inc www.peda.com message quickly pops up at the bottom then drops back down. It probably only stays up for a second. It only pops up once - you have to do another warm start to see it again.

Apparently, HP is using Peda's GrafEq graphic engine in the Advanced Graphing app. Some cool images can be seen in the GrafEq Gallery, including formulae if you click on each image.

This may be old news, but here is another link that mentions usage of GrafEq on the Prime.

Yes, the advanced graph application was developped by Pedagoguery Software Inc. I tried to draw the http://www.peda.com/grafeq/gallery.html graphs on HP Prime but I did not succeed for all.