Tetris in the HP50g

This is one of the times you feel stupid. You think you know quite well what you have, and there comes someone that shows you know nothing. 

Today, at work, I was using my HP50g, and a companion said to me: "wow, that's the calculator that comes with Tetris". 

"You mean you can load games, do you? of course you can find a lot of games for it", I replied.

"No, I mean that it comes with Tetris in its software", he said.

"I don't think so".

"Try this: open the formula editor (right arrow + EQW), set alpha, and write MINEISBETTER".

"Now, select it:"

"and now, de-select alpha and press "SIMP" (F6). Voilà!!"

You play it with the keys 2, 4 and 6 for movement across the screen, and 5 to rotate. Backspace to stop it.

Again: all the time in front of my nose, and I did not know!!