|Developer:||General Instrument, Yamaha|
1.) Square Wave and/or Noise
The YM2149, also known as the Software-Controlled Sound Generator or SSG, is modified AY-3-8910 re-branded by Yamaha. The chip has twice the resolution as the original, but a double-rate volume envelope table. Pin 26 can be used to halve the master clock when pulled low. This chip was used by the MSX2, MSX2+, MSX TurboR, Atari ST, and an assortment of arcade games. It has several revisions, one of which is the YM2149F which was embedded in several other chips including the YM2203, YM2608, YM2610, and Sunsoft's 5B chip.
Yamaha created several different variations of their YM2149, though they don't appear to have been used in any video game systems. If they are found to have been used in a video game system, they should be given their own section.
- YM3439 - a CMOS version of the YM2149. It was released as a 40-pin DIP (YM3439-D) and 44-pin QFP (YM3439-F).
- YMZ284 - a 16-pin YM2149. The parallel ports are removed and the three audio channels are mixed into a single sound output. Also, the 4/8 MHz selection pin and the /TEST pin have been removed.
- YMZ285 - a 28-pin YM2149 with a built-in PCM. The parallel ports are gone and there are two sound outputs. One is the three audio channels mixed, the other is for the PCM.
- YMZ294 - a 18-pin YM2149 without parallel ports. Mixes the three audio channels into a single output.
Over the years, a number of computers, video game consoles, and peripheral devices used the AY-3-891x series of chips. This is a chronological breakdown of those devices, and which chips they used.
Dozens of arcade games used the YM2149.
- This list is incomplete.
|YM2149 Manual||Download - (info)|
YM2149F on an Atari ST.