If you’ve been reading Engadget for a while, there’s a good chance your high school education involved using a scientific or graphing calculator during math class. Your old calculator might even be sitting in a desk drawer somewhere collecting dust. If you can’t find it, the Internet Archive’s latest project is here to help (via Ars Technica).

With the help of the team behind the Multi-purpose Emulation Framework (MAME), a project that has spent the past 25 years creating software that can emulate all sorts of gadgets, the archive now offers emulated versions of some of the most popular calculators of the past few decades. In all, The Calculator Drawer features 14 different models for Internet Archive visitors to noodle around, including the venerable Texas Instruments TI-81 from 1990.

Not every calculator of note from the past 25 years is part of the collection. For instance, you won’t find the Casio fx-7000g, the world’s first graphing calculator, on the list, but if you used a Texas Instruments or HP model back in school, there’s a good chance you’ll find something that should feel familiar. And if you feel a bit overwhelmed by all the buttons, worry not; the Internet Archive has also uploaded manuals for most of the included calculators.