Casio was just not prepared for the MZX line. A lot of new territory for them, and not enough time was spent on the OS development. The PX series uses essentially the same OS, but there is much more to the MZX version of that OS.

I would still recommend the CTX3000/5000 because it’s based on an OS Casio has been using for many years now. It’s menu driven, but they’ve had years developing it.

Sqk