knudsen@ihnss.UUCP (09/10/85)
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:
(1) Do you agree?
(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?
(4) Has anyone ever managed to record the whole "Marble Madness
Suite," so to speak? I'd pay money to get it all on a 45.
(5) Another possibility for the M.Madness game: Maybe the whole
sound track was just prerecorded in a studio , non-real-time,
with a 16-track tape, etc., and we're hearing just a CD Disk!
Makes sense: sometimes the game "loses" the music and takes a couple
seconds to pick up the track again.
Major argument against the CD theory: Some of the action
sounds (like rolling down the drain pipe) sound a lot like the
music itself, implying real-time synthesis on demand.
Or could those sounds be just stored in a big ROM?
Or does Atari have a *very* fast-random-access CD chassis?
(6) Is anyone out there working/playing/fooling with FM?
Do any commercial synthesizers use it much?
Keep your ears open, mike k.mahar@weitek.UUCP (mahar) (09/11/85)
In article <2614@ihnss.UUCP>, knudsen@ihnss.UUCP writes: > I've concluded that a large part of the MM game's music > is Frequency Modulation generated. Some questions: > > (1) Do you agree? Yep. All system I and system II game systems use a Yamaha FM sound chip set as well as one of the old "Pokey" sound generators. Paper Boy also has this chip set and has similar quality sounds. > (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. Your right. FM chips are not that hard to build. However, Yamaha has the basic patent on FM sound generation. Atari's lawyers didn't want to fight it so they just bought the chips from Yamaha. > (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? The Atari 800 and 400 as well as most of their coin-op video games used a Pokey chip (or several). This is just a counter which generates square waves at different frequencies. For sound effects, the Pokey has a Poly counter which is a cheap random number generator for white noise. > (4) Has anyone ever managed to record the whole "Marble Madness > Suite," so to speak? I'd pay money to get it all on a 45. Call Atari at (408)747-2700 and ask them. Or, talk to your local arcade operator. They can put the game in selftest mode and you can listen to any of the sounds on command. > (5) Another possibility for the M.Madness game: Maybe the whole > sound track was just prerecorded in a studio , non-real-time, > with a 16-track tape, etc., and we're hearing just a CD Disk! > Makes sense: sometimes the game "loses" the music and takes a couple > seconds to pick up the track again. Nope. The losses of sound are cause by a communication break down between the main processor and the processor controlling the sounds.
crandell@ut-sally.UUCP (Jim Crandell) (09/13/85)
In article <267@weitek.UUCP> mahar@weitek.UUCP (mahar) writes: >In article <2614@ihnss.UUCP>, knudsen@ihnss.UUCP writes: >> FM chip should be pretty easy to build. >Your right. FM chips are not that hard to build. However, Yamaha >has the basic patent on FM sound generation. Atari's lawyers >didn't want to fight it so they just bought the chips from Yamaha. Uh -- wait a minute. Exar was making an FM-able waveform generator chip (XR206, I think) fifteen years ago. Aren't you leaving out a significant part of the story? -- Jim Crandell, C. S. Dept., The University of Texas at Austin {ihnp4,seismo,ctvax}!ut-sally!crandell
granvold@tymix.UUCP (Tom Granvold) (09/14/85)
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I have found out some things about the Amiga sound hardware. Basically
the Amiga has four 8-bit D/A converters. This is how all the sound on the
Amiga is generated. Apparently there is a DMA channel, maybe more than one,
that will fetch the digital data and feed it to the D/A, releaving the CPU
chip from doing it. Someplace either in the operating system or one of the
custon chips is support for controlling the envelope. I hope to know more
of the details when I get to see the documentation. By the way, some of
the demo sounds for the Amiga were created by an add on A/D converter.
It doesn't sound like there is any possibility of doing FM
synthesis on the Amiga.
Tom Granvold
ucbvax!allegra!tymix!granvolddr_d@sftig.UUCP (D.Donahue) (09/16/85)
> > (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. > Your right. FM chips are not that hard to build. However, Yamaha > has the basic patent on FM sound generation. Atari's lawyers > didn't want to fight it so they just bought the chips from Yamaha. Mahar, I'm not certain what it is that you are refering to as far as Yamahas ownership with respect to FM sound generation. As far FM patenting is concerned, John Chowing of Stanfords CCRMA is the one who, perhaps didn't conceive of the idea, actively purued and developed the process of Frequency Modulated Sound Generation. The same John Chowning, not Yamaha, is the one who holds any patents having to do with FM Sound Generation. Doug Donahue AT&T Information Systems attunix!dr_d
mahar@weitek.UUCP (mahar) (09/16/85)
In article <2882@ut-sally.UUCP>, crandell@ut-sally.UUCP (Jim Crandell) writes: > In article <267@weitek.UUCP> mahar@weitek.UUCP (mahar) writes: > >In article <2614@ihnss.UUCP>, knudsen@ihnss.UUCP writes: > >> FM chip should be pretty easy to build. > >Your right. FM chips are not that hard to build. However, Yamaha > >has the basic patent on FM sound generation. Atari's lawyers > >didn't want to fight it so they just bought the chips from Yamaha. > > Uh -- wait a minute. Exar was making an FM-able waveform generator > chip (XR206, I think) fifteen years ago. Aren't you leaving out a > significant part of the story? Patenting FM synthesis is a lot like patenting the color blue to my mind. I'm well aware that others were there first. They didn't get that patent however. There exists a feature of patent law which makes an idea unpatentable if "it is obvious to anyone skilled in the art." I think FM qualifys here. Yamaha's lawyers have big teeth however, and Atari didn't want to mess with them.
mahar@weitek.UUCP (mahar) (09/19/85)
In article <590@sftig.UUCP>, dr_d@sftig.UUCP (D.Donahue) writes: > > > > (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. > > Your right. FM chips are not that hard to build. However, Yamaha > > has the basic patent on FM sound generation. Atari's lawyers > > didn't want to fight it so they just bought the chips from Yamaha. > I'm not certain what it is that you are refering to as far as Yamahas > ownership with respect to FM sound generation. As far FM patenting is concerned, > John Chowing of Stanfords CCRMA is the one who, perhaps didn't conceive of the > idea, actively purued and developed the process of Frequency Modulated Sound > Generation. The same John Chowning, not Yamaha, is the one who holds any > patents having to do with FM Sound Generation. Doug, You are right about Chowning. Yamaha bought exclusive rights to his patents. If you or I wanted to do FM we would still have to talk to Yamaha. Mike Mahar
sinclair@aero.ARPA (William S. Sinclair) (09/24/85)
Since we're on the subject of patents, Stanford U has the basic patent on
the FM process, as applied to music. Yamaha bought it from them after several
american companies had declined the option. Chowning did the research for
Stanford; as far as I know, he didn't get a very large chunk of the royalties,
if any.
Bill Sinclair