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The last SY99 memory expansion you'll ever need.

The Yamaha SY99 synthesizer shipped with a paltry 512KB of RAM^*, usable for sample and MIDI Data Recording storage. In 1991, if you were rich, you could add 5 additional 512KB memory expansion boards for a total of 3MB of storage.

Thanks to research completed by the Yamaha SY99 community over the past 25 years^†, it was discovered that the SY99 is capable of supporting up to 8MB of sample/MDR memory. Recent releases of high-density SRAM chips, coupled with a renewed interest in the SY99 itself, lead us to create the 8MB Magic Memory Board, or 8MB MMB for short^‡.

How it works

The SY99 has a dedicated memory bus for the sound generation hardware. This bus supports up to 32MB of 8-bit address space. The first 8MB of this space contains the Preset 1 and Preset 2 ROM waveforms. The last 16MB of space is reserved for the front-panel Waveform and Data cards, plus mapping for direct access to sound generation hardware (AFM, AWM, DSP, etc.).

The 8MB "hole" between these two chunks holds the default internal 512KB of RAM, as well as up to 5 SYEMB05 512KB expansion boards.

It turns out that with 3 small tweaks to the SY99 Operating System (OS), the 5MB hole from 12-16MB can also be allocated for use by samples and MIDI Data Recording!

The 8MB Magic Memory Board fills the entire space from 9½-16 MB using a single, modern 8MB SRAM chip, giving you the maximum possible sample/MDR storage with no SYEMB05 modules.^♣