A couple things I've learned (or deduced):[list=1][*]The editor
DOES NOT download a lookup table into EEPROM. (I verified this by examining the memory map in the editor.)[*]My initial guess was
incorrect that ATN is new with the 2.0 beta version of the editor. It
IS supported in all currently available versions (both Windows and DOS) of the editor for all versions of the BASIC Stamp 2. (It is
not supported by the DOS editor for the BS1.)[*]ATN is
NOT implemented in the editor (other than that it knows how to tokenize it for the BASIC Stamp.) It
IS implemented in the BASIC Stamp interpreter chip.[/list=1]I still don't know
HOW they implemented it.... (But then why should I care as long as it works.

) Joe, was your concern due to the fact that you thought it was implemented in the editor, and were therefore afraid that it would steal code space from you? If that's not it, I'm curious why you're not equally concerned about SIN and COS. Do you know of methods for calculating SIN and COS that are more efficient than any that you're aware of for ATAN?