page_title: General Instrument AY-3-8910
section_title: Variants
hierarchical_section_title: General Instrument AY-3-8910 / Variants
caption_attribution_description: English: AY-3-8910 compatible YM2149(SSG) made by yamaha.The package type of DIP 日本語: AY-3-8910互換 ヤマハ YM2149(SSG) DIP
context_page_description: The AY-3-8910 is a 3-voice programmable sound generator designed by General Instrument in 1978, initially for use with their 16-bit CP1610 or one of the PIC1650 series of 8-bit microcomputers. The AY-3-8910 and its variants were used in many arcade games—Konami's Gyruss contains five—and pinball machines as well as being the sound chip in the Intellivision and Vectrex video game consoles, and the Amstrad CPC, Oric-1, Colour Genie, Elektor TV Games Computer, MSX, and later ZX Spectrum home computers. It was also used in the Mockingboard and Cricket sound cards for the Apple II and the Speech/Sound Cartridge for the TRS-80 Color Computer.
  After General Instrument's spinoff of Microchip Technology in 1987, the chip was sold for a few years under the Microchip brand. It was also manufactured under license by Yamaha as the YM2149F; the Atari ST uses this version. It produces very similar results to the Texas Instruments SN76489 and was on the market for a similar period.
  The chips are no longer made, but functionally-identical clones are still in active production. An unofficial VHDL description is freely available for use with FPGAs.
context_section_description: The 8910 silicon chip was sold in three different packages.
  The AY-3-8910 has two general-purpose 8-bit parallel I/O ports, A and B, and these are available in the 40-pin package of the same name.
  The AY-3-8912 is the same chip in a 28-pin package, with parallel port B simply not connected to any pins. Smaller packages save cost and board space. The 8912 was the most widely used variant.
  The AY-3-8913 is the same chip in a 24-pin package, with both parallel ports not connected. Some users thought the small reduction in pin count over the 8912 made it less interesting; however, the I/O registers were rarely used by designers so General Instruments created this fully functional 24 pin alternative and released it approximately 6 months after the 8910 and 8912 chips.  The goal was to reduce complexity for the designer and reduce the foot print on the PCB.
  The Yamaha YM2149F 'SSG' chip has the same pinout as the AY-3-8910, with the minor difference that pin 26 could halve the master clock if pulled low. If left unconnected, as it would be if replacing an AY-3-8910 chip, an internal resistor pulls the pin high, so the master clock is not halved.
  The Yamaha YM3439 is a CMOS version of the YM2149F.  It is available in two packages: 40-pin DIP (YM3439-D) and 44-pin QFP (YM3439-F).
  The Yamaha YMZ294 is one of the newest variants of the YM2149, but in an 18-pin package. Has no parallel ports and only one sound output with the three channels mixed.
  The Yamaha YMZ284 is an even smaller variation of the YM2149, in a 16-pin package. It's basically YMZ294 without the 4/6 MHz selection pin and the /TEST pin.
  The Yamaha YMZ285 has a 28-pin package and features a built-in PCM. Has no parallel ports and two sound outputs: one with the three SSG channels mixed, other with the PCM output.
  The Toshiba T7766A is a compatible chip that has the same pinout as the AY-3-8910 and was used in some MSX models.
  The Winbond WF19054, JFC 95101 and the File KC89C72 have the same pinout as the AY-3-8910 and are also 100% software compatible. They're still in production and used on many slot machines.
  The AY-3-8914 has the same pinout and is in the same 40-pin package as the AY-3-8910, except the control registers on the chip are shuffled around, and the 'expected input' on the A9 pin may be different. Otherwise it is exactly the same as the AY-3-8910. It was used on the Mattel Intellivision.
  The AY-3-8930, also known as AY8930, is an enhanced but mostly-backwards-compatible version of the AY-3-8910. The function of the BC2 pin is changed (it is ignored and assumed to be 0 regardless of the pin state), otherwise the pinout is the same as the AY-3-8910. This variant of the chip adds a number of major enhancements, such as separate envelopes for the three channels (as opposed to one shared envelope), variable duty-cycles, more bits of precision for note frequency, volume, and envelope frequency, and a much more configurable noise generator. It was used on the Covox Sound Master sound card for the IBM-PC. Very few games took advantage of it beyond the normal AY-3-8910 features. This chip may have only been produced by Microchip Technology.
caption: YM2149F chip, 40-pin DIP package
exif: {}