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From: gnome@olivee.UUCP (Gary Traveis)
Newsgroups: net.micro.amiga
Subject: Re: FM Music Synthesis and Marble Madness
Message-ID: <478@olivee.UUCP>
Date: Fri, 13-Sep-85 12:04:35 EDT
Article-I.D.: olivee.478
Posted: Fri Sep 13 12:04:35 1985
Date-Received: Sat, 14-Sep-85 08:20:14 EDT
References: <2613@ihnss.UUCP>
Organization: Olivetti ATC; Cupertino, Ca
Lines: 34

> After several months of playing and listening to Marble Madness
> and tinkering with FM music synthesis on my home CoCo,
> I've concluded that a large part of the MM game's music
> is Frequency Modulation generated.  Some questions:
> 
> (2) Someone posted a rumor that the MM arcade game uses the
>     Amiga's sound chip set.  If so, does that imply that Amiga
>     supports digital FM synthesis?  Wow!  Actually, an LSI
>     FM chip should be pretty easy to build.
> (3) What techniques ARE used in the newer built-in home computer
>     sound chips?  The old Atari & Commodore chips were mostly
>     analog, right?  Are the new ones using digital filtering,'
>     AM, FM, or just good old waveform scanning with ADSR?

Ok, I have no knowledge of the above programs, but can comment on the
FM synthesis.

DK, Digital Keyboards, is planning on using a VLSI chip that
basically copies the DK/Crumar Synergy Digital FM synth.
The VLSI chip is being (or was) developed at a LSI company
founded by Hal Alles, formerly of Bell Labs Murray Hill.
I believe that the chip will have 32 digital oscillators
that are used to generate the waveforms.

You might try to find a copy of the Computer Music Journal (?)
or the published versions of the BTL  TM's that Hal wrote.
One of the journals deals with the "Portable digital synth..."
that was built at BTL-MH.

With the speed of present-day CMOS VLSI, it wouldn't be much
of a problem to stick a 32 oscillator FM synth on a chip.

Gary
(hplabs,allegra,ihnp4)oliveb!olivee!gnome