RE2-SN76489 - Project RE:birth 2nd Sound Card

What is it?

Project RE-birth 2nd is the spiritual continuation of Project RE-birth — a legendary open hardware project dedicated to bringing classic sound chips back to life.

In 2021, for unknown reasons, the Japanese closed the ym2203.com website, deleted all public schematics, and stopped the distribution of all peripheral hardware. Even with money in hand, it became impossible to purchase any SPFM motherboard or rebirth module. This was deeply frustrating for enthusiasts worldwide.

In the absence of original hardware, I forked almost all RE-birth music modules to truly revive this project. My mission: make classic sound chips available to people all over the world — no internal meetings, no mystery stores, no hunger marketing, just long-term stock and fair play for everyone.

The RE2-SN76489 is an SN76489 PSG sound card designed for the SPFM series. The circuit is fully redesigned and compatible with the RE:birth bus. It can be used with SPFM Light, SPFM Lite, RESPFM, IAP-RESPFM and other compatible motherboards.

About the SN76489 Chip

The SN76489 is Texas Instruments' iconic Programmable Sound Generator (PSG), featuring 3 square wave tone channels and 1 noise channel. It is one of the most recognizable chips in gaming history, powering the audio of the Sega Master System, Sega Mega Drive / Genesis (as a secondary PSG alongside the YM2612), BBC Micro, ColecoVision, TI-99/4A, and countless arcade boards.

The SN76489's crisp, buzzy square waves and characteristic noise channel are instantly recognizable to retro gaming fans. From Sonic the Hedgehog's jingles to BBC Micro game music, this chip's voice defined an era of home computing and gaming.

Key Features

• Authentic SN76489 PSG — 3 tone channels + 1 noise channel
• Compatible with RE:birth bus standard
• Works with SPFM Light, SPFM Lite, RESPFM, IAP-RESPFM and more
• Classic NE5532 dual op-amp for excellent audio output quality
• Adjustable volume control on-board
• Excellent digital-to-analog isolation for clean, noise-free sound
• Standardized RE:birth module form factor
• Long-term stock — always available, no artificial scarcity

Supported Chips

• PSG: SN76489, SN76489A, SN76496, NCT8496, SMSJ

Compatible Mainboards

• SPFM Light
• SPFM Lite (2 slots)
• RESPFM
• IAP-RESPFM (4 slots)
• STM32-RESPFM (4 slots)

Why Did I Make It?

The SN76489 is the perfect companion chip for OPN2/OPN2C modules — just as it was in the original Mega Drive hardware. Pairing a RE2-SN76489 with a RE2-YM2612 or RE2-YMF276 in your SPFM system gives you the complete, authentic Mega Drive sound experience: FM music from the YM2612 and PSG effects/jingles from the SN76489, exactly as the original hardware intended.

The RE:birth module design philosophy pursues the ultimate in sound quality, standardized appearance, and thoughtful bus layout with proper ground plane isolation — just like a textbook.