PythonExtra - A community MicroPython for CASIO calculators

Original MicroPython README: README-MicroPython.md.

This is a MicroPython port for fx-CG 50, fx-9860G III and related CASIO calculators.

Build instructions

Requires the fxSDK. Go to ports/fxcg50 or ports/fx9860g3 and run make. If it doesn't build, first try to use the dev branches for fxSDK, gint, fxlibc and JustUI. Rebuilds don't always work especially when checking out other commits (maybe my fault), so try to delete build if you think that's related.

Most of the code is in ports/sh and is shared between the platforms.

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Test suite

Located in ports/sh/examples.

• fx-CG: Whether the program successfully runs on PythonExtra on models of the fx-CG family. This is typically tested on a Graph 90+E but should include the fx-CG 10/20/50.
• G-III: Whether the program successfully runs on G-III models. This does not include older models like the fx-9860G II.
• Raw speedup: Speedup from using PythonExtra instead of the official Python app, without changing the code (as a ratio of execution times).
• Full speedup: Seedup from using PythonExtra-provided modules for rendering and input (usually gint), after changing the program's code.

Program	fx-CG	G-III	Raw speedup	Full speedup
Chute tridimensionnelle	Yes	Yes	x1.36	x2.26 ⁽¹⁾
Bad Apple	Meh⁽²⁾	-	TODO	TODO
Island of the Dead Kings	TODO	TODO	TODO	TODO
Synchro-Donjon (AI mode)	Yes	TODO	x1.82	-
Flappy Bird	Yes	Yes	x1.04	x2.35

⁽¹⁾ After upgrading to full-screen 396x224 instead of the original 120x80. (!)

⁽²⁾ Bad Apple requires unloading modules to not run out of memory, and I haven't been able to consistently do that. See the unload-modules branch.

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Basic benchmarks

PythonExtra is slightly faster than the official Python app, probably due to optimization during compilation of the VM. The tests below show the effect on basic Python operations.

Test	Program	Official Python (fx-CG 50)	PythonExtra (fx-CG 50)
VM speed	pe_loop.py (1 million pass)	~12 seconds	8.9 seconds
Shell output	pe_print.py (print 100000 integers)	~22 seconds	11.3 seconds
Large integers	pe_fact.py (compute 250!, 500 times)	~15 seconds	8.6 seconds

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TODO list

Bugs to fix:

• Fix not world switching during filesystem accesses (very unstable)
• Fix current working directory not changing during a module import (for relative imports)
• Fix casioplot not stopping on the last show_screen()

Python features:

• Compare features with existing implementations and other brands
• Get filesystem access (open etc) with the POSIX interface
• Get a decent amount of RAM not just the fixed 32 kiB that's hardcoded so far

UI:

• Add an option for fixed-width font which also sets $COLUMNS properly so that MicroPython paginates (requires better getenv/setenv support in fxlibc)
• Use unicode-fonts to provide Unicode support
  • Extend it with a fixed-width uf8x9 which maybe changes some glyphs (like i and l; the usual fixed-width unambiguous styles)
  • Try and provide a font smaller than 5x7 for more compact shell on mono
• A decent keymap that can input all relevant characters into the shell
• Features that would match MicroPython's readline:
  • Multi-line input (figure out how to store it); also, auto-indent
  • History (use MP_STATE_PORT(readline_hist) with readline_push_history() for a start); also, zsh-style search
  • Autocompletion (use mp_repl_autocomplete() which should hook just fine)

Future wishes:

• Build for fx-9860G II (requires manual filesystem support)
• Lephe's secret ideas (complete previous list to unlock)