Conference napalm::commusic_v1

    I've used it.  A few years ago I wrote a small assembly language
    wedge which would play a Vivaldi cello trio incessantly, independent
    of what the user was doing (programming, or whatever).
    
    It is a nice device for providing sounds for games.  It is very easy
    to get a wide variety of sounds.
    
    The sound quality, however, stinks.  The power supply is not well
    enough conditioned, and the whole thing is noisy as hell, from a
    musician's standpoint, anyway.
    
    If you packaged the sucker up in with a keyboard and played it in
    the music store, you wouldn't even give it a second thought.  Thin
    sounds, simple voice architecture, noise and all.
    
    Still, it was revolutionary compared to the Apple-IIs sound
    capabilities.
    
        
    Steph
    

    It's the SID chip in the C-64.  It's fully documented in the thick,
    plastic-comb-bound C-64 Programmers Handbook.  The thing has three
    oscillators, so you could do some reasonably complex *monophonic*
    sounds (rather than three one-oscillator sounds).  I don't know
    anything about its sound quality, though, so I defer to Steph's
    judgment here.
    
    You can cross modulate one of the oscillators with another, so you
    could maybe even do some 2-op FM with it!
    
    len.
    

    I got the sequential circuits keyboard which plugs into the joystick
    port of the c-64.  If you come out of the audio out, and run it
    thru about 12 noise gates, it's tolerable.   No, really, with a
    noise gate the sounds can be quite effective, but they should be
    monophonic to get the full range.  You do have several waveforms
    including a noise generator, (which my Akai AX-80 doesn't have),
    so even though it isn't a fairlight, it ain't bad.  If you only
    want a monophonic synth (non-MIDI) you can pick up an ARP odyssey
    for about $125 just about anywhere.

< Note 1026.0 by AKOV75::EATOND >
                          -< Commodore Synthesizer? >-

	I was in a local department store last night gazing at a Commodore
64 box when I noticed something that interested me.  The C64 has a 3-voice
internal synthesizer.  It said it put out sawtooth, square, variable pulse,
and noise, had an ADSR envelope gen., etc...

	Has anyone ever used these?  How does it sound?  My curiosity is
aroused.

	Dan

Hi Dan -

When I worked at Parker Bros. toys during the video game craze, I did the
sounds and music for the video games on the C64, Coleco, Intellivision,
Atari 2600,5200,400/800 etc. We used a Synclavier II to sample the sounds
off of the arcade machines (under license of course) and wrote some
sound spectrum analysis software to analyze the harmonic content. We then
wrote some software to pick the predominant harmonics and convert the
samples for each type of video game sound chip. The sound drivers for each
video game played back the converted samples with amazing results! The C64
and Atari 800 were the best. The sound effects were very close to the
original arcade. Using certain tricks, even the music was closely approximated.
The C64 was/is a primo game system, although memory and CPU speed are very
limited and the system software was always very primitive. With built-in
Basic it is a great little system for kids to learn on. The graphics and
sound are very well documented.

Dave

Block diagram of the C64 SID chip:


     +--------+              +---------+
     | DCO 1  |------------->|  DCA 1  |-----+
     +--------+              +---------+     |
     +--------+  ADSR             ^          |
     |  EG 1  |-------------------+          |
     +--------+                              |     +------+    +-----+
     +--------+              +---------+     +---->|      |    |     |
     | DCO 2  |------------->|  DCA 2  |---------->| DCF  |--->| DCA |--->
     +--------+              +---------+      +--->|      |    |     | AUDIO
     +--------+  ADSR             ^           | +->|      |    |     | OUTPUT
     |  EG 2  |-------------------+           | |  +------+    +-----+
     +--------+                               | |
     +--------+              +---------+      | |
     | DCO 3  |------------->|  DCA 3  |------+ |
     +--------+              +---------+        +----------- EXTERNAL INPUT
     +--------+  ADSR             ^
     |  EG 3  |-------------------+
     +--------+

There is also an ability to shut off osc 3 from the audio stream, and use
it to RING MODULATE osc 1 or to HARD SYNC to osc 1.  The filter can be
configured as a low pass, high pass, or band pass.  Sound incredible for
a little synth module in a small home computer?  It is, except for one
little detail.  The designers designed the filter wrong.  There was an 
article in IEEE Spectrum magazine on the case history of the C64.  
It explained that the mathematics used to design the filter chip was 
out to lunch.  Unfortunately it sounds like it when you set a resonance 
and sweep the center frequency.

Too bad.  The chip was made to allow for daisy chaining of other SID chips
so that a 12 voice synth could easily be made with 4 SID chips and some
sort of 8-bit microprocessor for control.  And the SID chips sell for less
than 10 bux apiece!

Todd.

RE < Note 1026.5 by HPSTEK::RHODES >

	So, there's no envelope applied to filter?

I don't think there is a H/W EG available for filter manipulation or for
the final DCA stage, however the application software can manipulate the 
filter parameters or final DCA output volume via software. (Basically 
you can build your own EGs in software.)  This implies that you can write 
software to create EGs that have unlimited (to a point) complexity - not 
just ADSRs.

I should point out that you can easily bypass the filter stage on the SID 
chip by setting a bit in one of its registers.  This would allow you to
use someone elses DCF chip and final DCA chip (like Solid State Micro 
Technology's) after the output stage of the SID chip.  The capability
to create a decent 12 or 15 voice multitimbral MIDI synth module using 
4 or 5 SID chips, one or more external DCF chips, and something like an 
8051 with built-in UART for MIDI for $200-$300 has existed for 5 years.
The only reason I didn't create such a device 5 years ago was that it 
was too expensive to manufacture a piano type keyboard.  MIDI has finally
made it acceptable to buy a synth with no keyboard attached to it.

Why didn't ARP or MOOG ever put out CV (Control Voltage) modules with 
no keyboard?  My guess is that at that time, the keyboard was the cheapest
part of the synth.  VLSI has made the keyboard's cost quite significant.

Todd.

    
>>Why didn't ARP or MOOG ever put out CV (Control Voltage) modules with 
>>no keyboard?  My guess is that at that time, the keyboard was the cheapest
>>part of the synth.  VLSI has made the keyboard's cost quite significant.
    
    Baloney! The analog keyboards were quite expensive. Analog keyboards
    which used the 1V/Oct "standard" used a single resistor per key with
    extremely low tolerance since they were constant-current devices.
    The Moog 12's keyboard used Burr-Brown op amps which cost about
    $130 alone! The resistors themselves cost approximately $40, and
    they still needed to be matched up after that. When they went to
    duo-phonic (two-voice) they were better at sensing voltage drops
    across multiple points, but they still weren't that cheap (this was in
    '73-'76 before they figured out how to make cheap resistive membranes).
    You also needed a diode and a cap for each key to debounce it for the
    gate and trigger circuit(s). 
    
    The Japanese were the ones who made keyboards into cheap stuff. 
    
    As for ARP not putting out CV modules with no keyboard, the 2500 series
    of modules did just that. you could buy a voltage controlled voice module
    which was 2 VCOs, 2 ADSRs, 1 multimode VCF, an LFO and a stereo VCA for
    about $1200. Moog's setup on the earlier synths just doesn't apply; they
    were somewhat more complicated since accuracy was difficult to achieve
    on the older modules. I still have the documentation for my dream system
    which was an $18K ARP 2500 system with three banks of modules, two two-voice
    keyboards (that was four whole voices!), 120-step by four-voice sequencing,
    and a raft of other toys. 
    
    For the record, the cheapest part of an analog synth was the VCA. Very
    simple circuit. The most expensive part was usually the VCO which needed
    extremely fine tolerances for linearity (the ear can tell!). The keyboard,
    as I said, got cheaper as the Japanese got into it, but in fact the
    circuitry for a keyboard is now quite simple compared to what it used
    to be like. believe it or not.
    
    /pjh

Salami!  Thanks for the info.  I feel better knowing that one existed.

Todd.

    
    I forgot to mention this also, but there was a wonderful add-on
    keyboard-less synthesizer (1V/oct) which Oberheim put out in the
    early '70s which had extra LFOs, and some other nifty stuff. Oberheim
    put a bunch of them into their original multi-voice synthesizers
    (a four-voice then an eight-voice). You used to have to take care
    of EACH VOICE with separate knobs - working the eight voice was
    exceedingly tiresome if you wanted all the voices to sound the same.
    It also cost a small fortune ($16K). Moog made it obsolete in 1976
    when they came out with that synth-on-a-chip and built the first
    really polyphonic synth. At least there were less knobs. 
    
    just one of the Oberheim expanders cost 1400 buckos.
    
    Anybody else remember those beasties?
    
    /pjh

RE < Note 1026.10 by FROST::HARRIMAN "The correct answer is 42." >

	If my recollections are correct, the Korg Mono/Poly worked on the
same principle - 4 voices either teamed together in one monster mono, or
all set precisely the same (ha) to produce a 4 voice poly unit.

	Dan

    Is it just me, or do I see a trend here of "boy those were the good
    old days"?  As for myself, I still have a Rhodes 73 suitcase, an
    ARP Odyssey (without the membrane-type pitch bend), an MXR Phas
    90 and a DOD Flanger that plugs into the wall.  And my Rhodes
    *still* sounds better than any DX7 pseudo Rhodes ever recorded.
    So there.  Nyyaaaah.

    Say wha'?????
    
    :^)
    
    Edd

    
    but who's Shirley anyway?
    
    Re: .12
    
    Egad. There's an old name. Aries. I built one of those back in the
    dark ages. Sold it to my high school. They still have it, apparently,
    and it's been over ten years.
    
    As far as "the good old days", I wasn't even trying to suggest that
    I'd ever want to go back to them without having the wonderful toys
    I have now! Are you kidding? No MIDI, hours and hours to set up
    patches, etc??? No. I still have my little Korg MS-20 to satisfy
    the urges to twiddle knobs and mate connectors with plugs (Now you
    can just leave that comment alone). But really, this was just a
    bit of nostalgia because things are so much different nowadays.
    
    Piano sounds were lousier then on synthesizers. There was no sampling
    technology, synchronization was VERY expensive (as opposed to just
    plain expensive nowadays), sequencers had finite (and quite limited)
    capacity and were constant-time-frame (as opposed to event driven)
    devices, jeezum crow, I could go on and on. 
    
    Nah, I like it better now, even if there aren't as many knobs to
    twiddle and parameters are soooo confusing.
    
    /pjh

    I'd like to throw in my two cents' worth, (while it's still worth
    a penny).
    
    None of the new synthesizers, in spite of their bang for the buck,
    can produce the genuinely individual and memorable sounds of minimoogs,
    prophets and the like. Who cares how many knobs need twiddling? At
    least the knobs are there and ready for twiddling, not implemented
    in some tangential fashion in an infinitely complex and uncognizable
    morass of software. I've heard loads of sounds from new synths that
    are impressive, but none so musical or uplifting as on the earlier
    instruments.
    
    Bu**s*** or what?
    
    Richard.

    
>    morass of software. I've heard loads of sounds from new synths that
>    are impressive, but none so musical or uplifting as on the earlier
>    instruments.
    
    umm, could it be that those who played in "the old days" possibly
    had a handle on making their instruments expressive? That's becoming
    a lost art again although I've heard some good stuff lately.
    
    I can reproduce many of the sounds, although the Moog sound was
    all in his 4-pole Butterworth filter. Nobody uses those anymore,
    and it's very difficult to take a simple sawtooth and put it through
    a 12 db-rolloff low-pass and have it sound the same as a 6 db-rolloff
    filter. Or a multimode filter, for that matter. You don;t see them
    anymore, but you see other things.
    
    Sounds like a reply to the "dream synth" topic back a wayz.
    
    /pjh
    

    Who says there aren't memorable sounds from todays synths.
    
    Those old subtractative beasts could never produce the kind of broad
    band noise I seem to get out of my DX without even trying.
    
    You want musical utility?  Oh.  That's another story.
    
    Steph
    

    re .19:  "broadband noise"
    
    Yeah, now that the first generation is obsolete, I gotta get me
    one of those Y-word machines for that grungy industrial sound. 
    Musically useful is in the eye of the beholder.  I'll admit I found
    the old VCO/VCF/VCA machines too mellow for my taste.
    
    	Eirikur
    

Has anyone heard of a Colortone keyboard? I am not sure if it was used on this
beastie or something else.  It plugged into the joystick port.  If it can still
be found, where?  I tried looking everywhere here in The Great White North, but
to no avail.