# pysega python based sega master system emulator

Python sega emulator

Sega Master System emulator written in Python.

Module dependencies:

pygame (1.9.4) or cyglfw or pyglet numpy (optional)

usage: __main__.py [-h] [-d] [-r REPLAY_FILE] [-s STOP_CLOCK] [-p {ntsc,pal}]

[-g {pygame,cyglfw,pyglet}] [--cpu {cpu}] [-a {sounddevice,pygame}] [-n] cartridge_name

Sega emulator

positional arguments:

cartridge_name

optional arguments:

-h, --help

show this help message and exit

-d -r REPLAY_FILE, --replay_file REPLAY_FILE

Json file to save/restore state. Triggered via '[',']' keys (default: None)

-s STOP_CLOCK

Set a clock time to stop (useful for profiling), setting to '0' is disable stop (default: 0)

-p {ntsc,pal} Select the palette to use (only changes color, not

timing). (default: ntsc)

-g {pygame,cyglfw,pyglet}

Select an alternate to graphics module (default: pygame)

--cpu {cpu} Select an alternate CPU emulation, primarily to allow

trying different optimisations. (default: cpu)

-a {sounddevice,pygame}

Select an alternate CPU emulation, primarily to allow trying different optimisations. (default: pygame)

-n	Wishful flag for when the emulator runs too fast. (default: False)

Keys

arrow keys - move z - Fire A x - Fire B r - Reset

Example startup

Examples (pygame audio by default, I struggle to get non-flakey audio, but pygame 1.9.4 on generates reasonable sound.):

python -m pysega myrom.sms

Issues:

TODO:

• Improve Audio with python. With this chip, pygame produces reasonable results. There's a trade between lag and buffer size. (pygame 1.9.1 segfaults with audio, not sure if there's something wrong in my usage, but 1.9.4 appears ok).
• Check instruction cycles (emulation appears tollerant to errors in cycles for each instruction, but would be good to get correct).
• Add more regression tests
• Add profiling tests
• Add travis-ci, coverage checks.