Atari AMY, for additive musical synthesis, was a 64-oscillator additive synthesizer implemented as a single-IC sound chip. It was developed by Atari, Inc. as part of a new chipset, codenamed "Rainbow" that included a graphics processor and sprite generator. Rainbow was considered for use in the 16/32-bit workstation known as Sierra, which existed in prototype form circa 1983, but the Sierra project was bogged down in internal committee meetings. Rainbow development continued up until Atari's games console and home computer divisions were sold to Tramel Technology, which became Atari Corporation. For a time, AMY was slated to be included in the Atari 520ST, then an updated version of the Atari 65XE, the 65XEM, but development was discontinued. 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.