RE2-SAA1099 - 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-SAA1099 is an SAA1099 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 SAA1099 Chip

The SAA1099 is Philips' distinctive 6-channel stereo sound generator, featuring 6 square wave tone channels with individual stereo panning, 2 noise generators, and 6 envelope generators. It is best known as the sound chip of the SAM Coupé home computer and the Creative Music System (CMS) / Game Blaster — the predecessor to the Sound Blaster card.

The SAA1099's stereo capabilities and rich 6-channel architecture give it a unique character among PSG-class chips. Its envelope generators allow for more expressive, dynamic sound than typical square-wave PSGs, making it a fascinating chip for chiptune composers and retro hardware enthusiasts.

Key Features

• Authentic SAA1099 — 6-channel stereo PSG with envelope generators
• 6 independent stereo-panned tone channels
• 2 noise generators
• 6 envelope generators for expressive dynamics
• 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

• SAA: SAA1099, SAA1099P

Compatible Mainboards

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

Why Did I Make It?

The SAA1099 is one of the most underappreciated sound chips of the 8-bit era. Its stereo output and envelope generators set it apart from the AY/SN PSG family, and the Game Blaster / CMS card gave it a brief but memorable presence in PC gaming history. The RE2-SAA1099 brings this rare chip into the modern SPFM ecosystem, letting enthusiasts explore its unique sonic character through VGM playback and live experimentation.

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.