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?
Keep your ears open, mike k.gnome@olivee.UUCP (Gary Traveis) (09/13/85)
> 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: > > (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