Key pressing slows down program execution?

[Tim Wessman]

The slowdown isn't on the calculator code side due to any checking, but rather some poorly written OS behaviors and drivers that we don't have any ability to change. From memory, the keyboard driver spawns some threads, triggers some interrupts and runs on timers. Its a really poor design and implementation. Pressing a key triggers all sorts of behavior in the background that interrupts the main application thread and chews up time.