If you aren't looking for cycle-accurate hardware emulation but simply want to run BASIC code, you can use modern interpreters. Since the FX-880P ran a version of BASIC, many users opt to rewrite their old scripts in or FreeBASIC on modern PCs. While this isn't a true "Casio FX-880P emulator," it preserves the logic and functionality of the original programs with much better speed and display resolution.
The FX-880P had a built-in "Library" key containing hundreds of pre-programmed scientific formulas (calculus, statistics, physics). For quick calculations, having this available on a modern PC or tablet via an emulator is incredibly convenient. casio fx-880p emulator
This writes "A" to the top-left pixel block. Useful for simple graphics. If you aren't looking for cycle-accurate hardware emulation