aldenbradford.com/calculator_emulator
The calculator above really works! Push some buttons, try it out!
Some of the buttons on the calculator are also tied to keys on your keyboard. You can type the numbers directly from your keyboard if that's easier for you. The backspace key does backspace, enter and = both work for equals.
If you are showing this in front of a class, you may wish to use the "show history" feature, which you can enable with the checkbox above. This will show the sequence of buttons you pressed to the right of the calculator. If you click on a button in the history, the calculator resets to the time when you pressed that button.
I have attempted to make this calculator behave as close to the real thing as possible, by a process of reverse engineering. Not every feature is implemented yet, so if what you are trying does not work, you may be able to see why in the debug information below. If you would like to implement a missing feature, I do accept pull requests on Github.
This is an ongoing project by Alden Bradford, started circa January 29, 2021. For details on how it works, a roadmap for future features, and copyright information please see the associated Github repository. This software is, and will always be, completely free. If you have found it useful, please send me an email to let me know. May this tool help us all to know our calculators better.
Below is a view onto what's going on inside the calculator. This is very helpful for debugging.
current calculator state.