About
The Sunsoft 5B is a chip manufactured by Yamaha, for Sunsoft. While used interchangeably with the Sunsoft FME-7, and the Sunsoft 5A, the only game to utilize the audio was in the Famicom game Gimmick!. Due to Yamaha's manufacturing, it is a clone of their own chip, the YM2149F, which itself is a clone of the AY-3-8910. The chip has 3 channels of audio, capable of Tone (square waves), 32 pitches of Noise, and a user configurable Envelope generator. However, despite these features, Gimmick! only used the Tone capabilities of the chip.
Instruments
Instruments on the Sunsoft 5B are fairly close to the 2A03. However the
biggest difference lies in the Noise/Mode macro, which replaces the Duty
macro present on the 2A03. This macro allows one to toggle noise, tone,
and envelope on the channel, also allowing one to freely mix between the
three.
Another major change from the 2A03's instruments lies in the volume.
While the 2A03's design gives it linear volume, the Sunsoft 5B has
what is "exponential volume", which behaves differently than the 2A03's
linear volume.
Noise/Mode Macro
The Noise/Mode macro present in Dn-FT is relatively simple. There are three bars, one for each "mode", which can be freely toggled. Above is a slider allowing for the user to define what specific pitch they want, of the 32 available pitches. For reference, the Blue bar is for Tone, the Pink is for Noise, and the Yellow bar is for Envelope.
5B Envelopes
The Sunsoft 5B has a configurable envelope generator, able to play back 16 preset envelope sets. The table below shows each envelope and its functions.
| H0y Hex Command | Envelope Shape | Envelope Description |
|---|---|---|
| $0 to $3 |  |
A one-shot decay envelope. Usually used at extremely low frequencies mixed with tone to produce a hardware decay envelope. |
| $4 to $7 |  |
A one-shot attack envelope. |
| $8 |  |
Looped decay envelope. Functionally identical to a sawtooth wave at audible frequencies. |
| $9 | |
Identical to $0. |
| $A |  |
Looped Decay and Attack envelope. Identical to a symmetrical sawtooth wave, referred to as a "triangle" wave. |
| $B |  |
One-shot decay envelope. Holds the output at maximum volume when finished. |
| $C |  |
Looped attack envelope. Functionally identical to envelope $8 at audible frequencies. |
| $D |  |
One-shot attack envelope. Holds the output at maximum volume when finished. |
| $E |  |
Looped Attack and Decay envelope. Virtually identical to $A. |
| $F | |
Identical to $4. |