It was developed by Atari, Inc. as part of a new chipset, codenamed "Rainbow" that included a graphics processor and sprite generator.
The technology was later sold, but when the new owners started to introduce it as a professional synthesizer, Atari sued, and work on the project ended.
The AMY also included a number of ramp generators that could be used to smoothly modify the amplitude or frequency of a given oscillator over a given time.
The result is a highly accurate rendition of the original signal, but reduced to a handful of parameters that could easily be stored.
[1] The Amy team was led by Gary Sikorski, and the primary architects were Scott Foster and Steve Saunders.
The single-chip implementation was handled by Sam Nicolino, while Jack Palevich[a] and Tom Zimmerman wrote support software.
[1] Amy was announced in an Atari-internal mailing list in March 1984, with a short description and a June estimated time frame for shipping the first version, the AMY-1, with volume quantities available that December.
Sierra used Amy for sound and a pair of chips code-named "Gold" and "Silver" for graphics, and was considering either the intel 286 or Motorola 68000 as its CPU.
[7] However, as the company's focus quickly shifted from the 8-bit line to the new ST's being launched at the same time, the XEM was shunted aside and never released commercially.