This document serves as an appendix for the Yamaha SY99 synthesizer. It provides supplementary technical details intended for advanced programmers and users who wish to customize or understand the instrument's internal capabilities.
The text covers a wide range of topics including detailed explanations of preset voices, drum layouts, AFM algorithms, and ROM hybrid synthesis techniques. It also includes information on using loaded samples, master control functions, MDR functions, error messages, disk file extensions, and the Standard MIDI File Format.
The document includes a specific section dedicated to explaining how the SY99 differs from the SY77.
ROM hybrid synthesis is a feature discussed in this appendix, with instructions on how to use it found in section 310.