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SN76489 Synthesizer Plugin by Aly James Lab
15.00 €
SPSG by Aly James Lab is a Virtual Instrument Audio Plugin for Windows. It functions as a VST Plugin.
Windows XP/7/8.
Multi-core compatible VST host.
Sample Formats
Loads and/or Saves
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SPSG (Super Portable Sound Generator) is a VST synth that not only emulate the Sega Master System sound chip SN76489 but also adds a lot of extra features:


SPSG is a closely modeled Sega Master System sound chip (SN76489) emulator, a Windows VST instrument with live control in mind. Many test on real hardware have made possible some unreleased extended features, SPSG unlock the full power of the PSG (also known as DCSG, was also the second Sega Megadrive sound chip).

You may think, the SN76489 chip is basically square waves and 8-bit noise... but there is more. Clever programming tricks can unlock some awesome potential.

S-PSG adds many extended features to squeeze to most of the sound chip and a huge user friendly GUI. It is a fantastic synth suitable for chip music and SEGA nostalgic pleasure and also a powerful 8-bit tool for modern music production.

With the help of complex features like multi-steps envelopes, programmable arpeggios, circuit bending options, sequenced tables and precise accurate control over the master clock rate, you will be able to reach classic gaming sounds of that era but also some hard to make type of sounds which, in the good old days, needed to go down to assembly language to perform...

Advanced techniques like Timer Interrupt modulation and PCM sample playing are supported and even the AY3-8910 (similar sound chip found in the ZX Spectrum) Hardware envelope has also been included as an emulated feature.

SPSG had been developed using custom C++ code and 3r party licensed code.

Runs on Windows 32/64-bit Systems and is multi-core compatible with 32-bit DAW/Host.

Global Features:

  1. User Friendly GUI: Big size, different panels for controls...
  2. Full MIDI Automation: With MIDI learn (right click to assign any MIDI message).
  3. Poly & Mono Mode: with Portamento Control.
  4. Output Filtering: Direct, Master System or Genesis / Megadrive.
  5. MIDI IN & OUT: Outputs amplitude & pitch envelope with hardware compatibility.

SN76489 Native Features:

  1. Support any clock rate: From 1 MHz to 4 MHz like the real chip.
  2. 1-64 STEPS Amplitude & Pitch Envelope Generator: 64 steps persistent memory, up to 300 Hz, synced or independent speed rate, loop, ping-pong, delay and release step.
  3. LFO Vibrato: For quick expression.
  4. Internal Arpeggiator: Programmable or live controlled via MIDI Input.
  5. Memory Slots & Tables: 8 memory slots per envelope, arpeggiator and advanced waveforms than can be internally sequenced at any available clock speed.(can be used as a wave-table for software waveforms).
  6. PCM & PWM: 3 slots to load any PCM WAV files, auto converted to mono that will be played to the SN76489 volume register on one or three channels at the time. Two modes for playing are available: PCM(4-bit) or PWM(1-bit).

SN76489 Extended Features:

  1. Z80 Software Timer: Z80 Timer Interrupt routine pulse width modulation. "SID" lead Sound or custom waveforms. It can also synced the AY3-8910 hardware envelope generator for SYNC type effect.
  2. AY3 8910 Envelope Generator: Optional AY3-8910 emulated envelope generator (Buzzers, Sync Buzz etc..a feature that was only available on the AY3 and YM2149 sound chips; ZX spectrum, MSX, Atari ST).
  3. Noise Channel LFSR circuit bending: the LFSR generator is tweak-able in real-time (tapped bits mask and feedback bit) from the original fixed 16-bit configuration of the Sega Master System/Genesis, to anything in between...which basically gives you the ability to reach some different sound chips type of noise or mess it up in a unique way, all of that in real-time.


  • Load & Save Full Patch & Banks in FXB/FXP.
  • Controls the real Mega Drive hardware via MIDI: Requires Little Scale GENMDM MIDI Device (not available ATM).
  • Controls the real SN76489 sound chip via MIDI: DIY ATMEGA controlled device that you can built (Open Source Code available on request).

Everything SPSG does was and is possible on the hardware.

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