41z module "NO LIBRARY"

[Ángel Martin]

Yes you need the Library#4 installed (i.e. plugged) into port-4; I don't know how that'll be done on i41CX but I assume there is a way to do it?

Once that's out of the way you need to power-cycle the calculator so that the z-Stack buffer is created. Alternatively you can execute the function "-HP-41Z" (the name includes the hyphen) which basically does the same thing.

Good luck, a treasure trove awaits you ;-)