Reading and understanding DATA sheets

OK I stand corrected, I never thought to look in the 16 bit compiler.
Oshonsoft PIC Basic IDE does not support 12f1840 but it does suppoert 12f683
Oshonsoft PIC16 Basic IDE supports 12f1840 but not 12f683.

So as I think jjw is saying, if you only have the PIC Basic IDE license, no 12F1840 support.