Speed comparison Swissmicros / HP

[HrastProgrammer]

So, DM-41L running at 48MHz on LPC1115 (32-bit ARM RISC CPU) runs just slightly faster (73.7 vs. 87.6 sec) than the original HP-41CV while 15+ years ago I was able to emulate HP-41C/CV/CX which runs ~3x (HP-41X) and ~1.8x (HP-41E) faster than the original, all this on an ancient HP-48GX (4-bit "stone age" CPU at ~3.8MHz)!

The only logical explanation is that display refresh takes an enormous amount of time on DM-41L. Try to disable a goose - put some ALPHA text on the display at the start of the program and report the results ...