PSA: Here's another, much more feature-rich calculator called Expression Calculator (or Global Calculator sold in Germany in 1997), written in Delphi - https://

PSA: Here's another, much more feature-rich calculator called Expression Calculator (or Global Calculator sold in Germany in 1997), written in Delphi - https://github.com/dblock/excalc https://github.com/dblock/excalc, full source code and a working executable that still runs on any version of Windows.