ay8910-wrapper 0.7.2

A Python wrapper for the AY-3-8910 and AY-3-8912 sound chip emulators, featuring real-time audio playback and cycle-accurate synthesis.

AY-3-8910 Standalone Library and Python Wrapper

A Python wrapper for the AY-3-8910 and AY-3-8912 sound chip emulators, featuring real-time audio playback and cycle-accurate synthesis.

A Note on this Project's Origin

This project is primarily the result of a series of experiments using various IA Code Assists for code generation and error handling. Rather than using it on academic examples, it seemed more interesting to apply it to a project that could meet a real practical need.

This, therefore, is the reason for AY8910's existence: you can dissect the code to see how Gemini and Junie (with my guidance) went about building it, or you can ignore all that and just use this library for your own needs!

This project contains a standalone C++ library for the AY-3-8910 sound chip. It features two emulation engines:

• Caprice32-based (ay8912_cap32): The recommended engine for all new projects. It offers superior accuracy, stereo mixing, and integrated live audio support.
• MAME-based (ay8910): Kept primarily for historical reasons and legacy compatibility.

It also includes a Python wrapper to make these emulators accessible from Python scripts, allowing for programmatic chiptune generation and .ym file playback.

Quick Start (Live Audio)

import ay8910_wrapper as ay
import time

# Initialize
psg = ay.ay8912_cap32(1000000, 44100)
psg.set_stereo_mix(255, 13, 170, 170, 13, 255)

# Start live playback!
psg.play()

# Set registers - sound changes immediately
psg.set_register(0, 254) # Tone A Fine
psg.set_register(1, 0)   # Tone A Coarse
psg.set_register(7, 0x3E) # Enable Channel A
psg.set_register(8, 15)   # Max volume

time.sleep(1)
psg.stop()

# Play a .ym file using the new live script
python scripts\ym_live_player.py PATH\TO\YM_FILE.YM

Installation

You can install the library directly from PyPI:

pip install ay8910_wrapper

This will automatically install the necessary dependencies (lhafile, numpy, sounddevice).

For developers who want to compile from source or contribute, please refer to the Contributing Guide.

Basic Usage in Python (Legacy MAME engine)

Note: This section demonstrates the legacy ay8910 class. For modern applications, please refer to the Quick Start section or the Caprice32 section below.

import ay8910_wrapper as ay
import wave
import struct

# Helper to write WAV files
def write_wav(filename, samples, sample_rate):
    with wave.open(filename, 'wb') as f:
        f.setnchannels(1)
        f.setsampwidth(2)
        f.setframerate(sample_rate)
        packed_samples = struct.pack('<' + 'h' * len(samples), *samples)
        f.writeframes(packed_samples)

# --- Main Program ---

# 1. Initialize the emulator
clock = 2000000  # 2 MHz, a common clock for this chip
sample_rate = 44100
psg = ay.ay8910(ay.psg_type.PSG_TYPE_AY, clock, 1, 0)
psg.set_flags(ay.AY8910_LEGACY_OUTPUT)
psg.start()
psg.reset()

# 2. Program the chip registers
# Enable Tone on Channel A, disable everything else
psg.address_w(7)
psg.data_w(0b00111110)

# Set Channel A frequency to Middle C (261.63 Hz)
period = int(clock / (16 * 261.63))
psg.address_w(0)  # Fine tune
psg.data_w(period & 0xFF)
psg.address_w(1)  # Coarse tune
psg.data_w((period >> 8) & 0x0F)

# Set Channel A volume to max
psg.address_w(8)
psg.data_w(15)

# 3. Generate audio
# Generate 2 seconds of audio
num_samples = sample_rate * 2
samples = psg.generate(num_samples, sample_rate)

# 4. Save the result
write_wav("tone_output.wav", samples, sample_rate)
print("Generated 'tone_output.wav'")

For a complete list of all available functions, classes, and constants, please see the API Reference.

Recommended: Caprice32 (Amstrad CPC) Emulation

The Caprice32 engine is the preferred choice for most users. It provides more authentic sound synthesis and advanced features like stereo panning.

# Initialize the Caprice32-style emulator
psg_cpc = ay.ay8912_cap32(clock, sample_rate)
# Set standard CPC stereo mix (Channel A=Left, B=Center, C=Right)
psg_cpc.set_stereo_mix(255, 13, 170, 170, 13, 255)

# Generate stereo audio (interleaved)
stereo_samples = psg_cpc.generate(num_samples)

Contributing Guide

If you wish to contribute to the project or compile it from source, please refer to our Contributing Guide.

It contains all the necessary information about:

• The development workflow (GitHub Flow)
• Using uv for environment management
• Compilation and test commands
• Continuous integration processes (GitHub Actions)

Acknowledgments

This project relies on the incredible work of the following open-source projects:

• MAME: The original AY-3-8910 and YM2149 emulation cores were derived from the MAME project. Their commitment to accuracy and historical preservation is a cornerstone of this library.
• Caprice32: The Amstrad CPC-specific PSG emulation logic and amplitude tables were integrated from the Caprice32 project, providing authentic sound for CPC-related audio tasks.
• Sergey Bulba: Special thanks for the AY/YM amplitude tables used in the Caprice32 engine, which are essential for reproducing the characteristic sound of these chips.