CAS Programming

The Nspire's standard OS ("Phoenix") contains CAS programming capabilities similar enough to those of the TI-68k's standard OS ("AMS").

• On Phoenix, Quantum / ESQ are 2 bytes, while they're 1 byte on AMS.
• Many entry points described in the documentation of GCC4TI or TIFS exist on Phoenix; however, there's no equivalent of the AMS jump table on Phoenix.
• The higher-level functions (or their wrappers for execution as part of a BASIC program) are accessible through primary_tag_list, fairly similar to that of AMS. The addresses of lower-level functions and variables (e.g. next_expression_index, push_quantum, top_estack, NG_control, and many others) need to be found from those, on a per-OS basis...
• We don't yet have any documentation about OS integration (reading from variables and storing to variables; being accessible from a Calculator screen, which probably means exporting BASIC functions and embedding a Ndless program into a regular document).

A rough proof of concept for native EStack programming (on Phoenix 1.7.2741 CAS only, as of 2011/05/01) can be downloaded from http://www.ticalc.org/archives/files/fileinfo/437/43727.html.