This is not part of the lab itself, but in case you are interested, here's why the save-page won't work: because the machine cycle simulator page is generated using Javascript. Javascript is a language which can be embedded inside a page, and is executed by the browser. HTML is a declarative language: it describes what the page should look like, and the browser makes it so. Javascript is a procedural language: it actively executes instructions, and can interact with the mouse, keyboard and the network. Javascript can also make the page change by dynamically updating the HTML.

The simulator page relies on Javascript for most of what it does; only the title directory areas on the left and top are generated from HTML. The simulator is entirely Javascript running the browser. So what you see is not really the page that was received from the server, but the results of the Javascript running after the page was received. But save-page means to save the original page, not the current one. It's the print function that shows the browser window.

So save-page will save the original page discarding everything you did in lab. If you want to retain that information, you need to use print.