Your description immediately made me think of the TI SN76577 "Complex Sound Generator" IC [1]. If I'm not mistaken it was used in the early versions of the MB G

Your description immediately made me think of the TI SN76577 "Complex Sound Generator" IC [1]. If I'm not mistaken it was used in the early versions of the MB Games Electronic Battleship game (think falling missile and white-noise explosion sounds). Edit: Not a decap, but this page [2] has links to the datasheet and other reference material that includes a block diagram, and even has circuit diagrams of the internal circuitry. Edit 2: A video [3] demonstrating some of the possible sounds. [1] https://en.wikipedia.org/wiki/Texas_Instruments_SN76477 https://en.wikipedia.org/wiki/Texas_Instruments_SN76477 [2] http://sandsoftwaresound.net/sn76477-complex-sound-generator/ http://sandsoftwaresound.net/sn76477-complex-sound-generator... [3] https://www.youtube.com/watch?v=atH1MvXDYYE https://www.youtube.com/watch?v=atH1MvXDYYE