Согласен, понять трудно. Вот как все начиналось (цитата из InfoWorld от 28 января, 1985).
According to Atari president Sam Tramiel, engineers couldn't complete another version, the Atari XEM music micro, which is the same as the 65XE except for its «Amy» music chip. Sam Tramiel calls it «the only thing left over at the old Atari that was any good.»
The XEM is supposed to produce eight independent voices and will create new interest in computer-generated music, says Zeb Billings, president of Sight & Sound Music Software Inc. of New Berlin, Wisconsin. Sight & Sound, a 20-year-old company in the music business, writes all the software for Casio electronic music peripherals. Billings says his company will be working with Atari on music software for the new computer.
«This chip is so highly advanced that if you close your eyes, you can't tell if the music is coming from a piano or the computer», Billings says. «The cello sound is so real that you can almost smell the resin on the bow.»
In accordance with Tramiel tradition, Tramiel and his troops promised low prices on all products «designed for the masses.» The XEM should retail for less than $150.00.
Ray Tabs, вице-президент Sight & Sound, на своей страничке LinedIn по поводу опыта работы в 80-х указывает: «Took Sight & Sound into the new music technology. Purchased a non-working VLSI chip from Atari. Developed the chip into a working VLSI music synthesis chip». (https://www.linkedin.com/pub/ray-tabs/8/a95/870).
Еще один из работников этой компании пишет в комментариях: «I was part of the company that bought the AMY sound chip technology from Atari. We’d hoped to use it at the heart of new synthesizers. As a digital additive synth, our software and methods quite resembled the technology that would become MP3. We had very rich sounds compressed to an unprecedented degree». (http://www.dadhacker.com/blog/?p=1000).
И вот, как все закончилось: «The Amy chip and technology were sold to a Millwaukee based audio design house called Sight & Sound. The company was able to not only decypher the workings of the Amy, but created a newer and more powerful version which they intended to market. However Atari suddenly reappeared on the scene and initiated a law-suit that apparently was so frightening that many of the former S&S employees that have been interviewed for the research on the Amy chip would only talk under anonymity. The Amy chip, its technology and its enhanced replacement would not only never be used by S&S, but Atari never utilized the technology either. The designs, equipment and chips lanquished in a warehouse until 1998 when the company was liquidated and everything was sold off or destroyed.» (http://www.atarimax.com/jindroush.atari.org/achamy.html)
Мой приоритет — достаточно эффективная работа аудио плагина в DAW на современном PC. В такой ситуации, думаю, нет особенного смысла переходить на фиксированную запятую (хотя такой вариант и сейчас востребован в приложениях, где требуется побитовая точность результата). Что касается микроконтроллеров, то я бы, скорее, изменил алгоритм передискретизации. Кстати, CIC-фильтры, о которых я упомянул в «Заключении», в данном случае интересны тем, что работают как раз на фиксированной запятой и не требуют операций умножения.
Мне думается, что каждый эмулятор хорош в свой области применения. Ayumi далеко до возможностей и быстродействия ZXTune. Звучание Ay_emul кому-то может показаться более приятным, чем «стерильный» звук Ayumi. НЧ-фильтр Ay_emul просто может более адекватно отражать особенности
звуковоспроизводящего тракта, к которым привык слушатель. У меня реального чипа для проверки нет, но я помню, что MmcM делал тест на 96 кГц и остался доволен результатом.
Хочу добавить, что статья это была написана вовсе не для рекламы Ayumi. Задача передискретизации возникает и при моделировании Pokey, Paula и прочих звуковых чипов. Я надеюсь, что моя статья хоть немного облегчит жизнь авторам будущих эмуляторов. :)
According to Atari president Sam Tramiel, engineers couldn't complete another version, the Atari XEM music micro, which is the same as the 65XE except for its «Amy» music chip. Sam Tramiel calls it «the only thing left over at the old Atari that was any good.»
The XEM is supposed to produce eight independent voices and will create new interest in computer-generated music, says Zeb Billings, president of Sight & Sound Music Software Inc. of New Berlin, Wisconsin. Sight & Sound, a 20-year-old company in the music business, writes all the software for Casio electronic music peripherals. Billings says his company will be working with Atari on music software for the new computer.
«This chip is so highly advanced that if you close your eyes, you can't tell if the music is coming from a piano or the computer», Billings says. «The cello sound is so real that you can almost smell the resin on the bow.»
In accordance with Tramiel tradition, Tramiel and his troops promised low prices on all products «designed for the masses.» The XEM should retail for less than $150.00.
Ray Tabs, вице-президент Sight & Sound, на своей страничке LinedIn по поводу опыта работы в 80-х указывает: «Took Sight & Sound into the new music technology. Purchased a non-working VLSI chip from Atari. Developed the chip into a working VLSI music synthesis chip». (https://www.linkedin.com/pub/ray-tabs/8/a95/870).
Еще один из работников этой компании пишет в комментариях: «I was part of the company that bought the AMY sound chip technology from Atari. We’d hoped to use it at the heart of new synthesizers. As a digital additive synth, our software and methods quite resembled the technology that would become MP3. We had very rich sounds compressed to an unprecedented degree». (http://www.dadhacker.com/blog/?p=1000).
И вот, как все закончилось: «The Amy chip and technology were sold to a Millwaukee based audio design house called Sight & Sound. The company was able to not only decypher the workings of the Amy, but created a newer and more powerful version which they intended to market. However Atari suddenly reappeared on the scene and initiated a law-suit that apparently was so frightening that many of the former S&S employees that have been interviewed for the research on the Amy chip would only talk under anonymity. The Amy chip, its technology and its enhanced replacement would not only never be used by S&S, but Atari never utilized the technology either. The designs, equipment and chips lanquished in a warehouse until 1998 when the company was liquidated and everything was sold off or destroyed.» (http://www.atarimax.com/jindroush.atari.org/achamy.html)
звуковоспроизводящего тракта, к которым привык слушатель. У меня реального чипа для проверки нет, но я помню, что MmcM делал тест на 96 кГц и остался доволен результатом.
Хочу добавить, что статья это была написана вовсе не для рекламы Ayumi. Задача передискретизации возникает и при моделировании Pokey, Paula и прочих звуковых чипов. Я надеюсь, что моя статья хоть немного облегчит жизнь авторам будущих эмуляторов. :)