Blitter

C64 SID

The SID CMOS IC in the C64 delivers an interesting eight bit sound colour in the C64

When I first heard the C64 SID as a kid it was nothing to throw your hat at. I've had experiences with concert piano's, tenor saxophones, percussion instruments in the electric range professional synths, bass guitars so I knew this bleep bloop ssshtt IC could never sound the way of the pro musical hardware, especially not the acoustic instruments.

Last Ninja I

It was when I heard the music of Last Ninja I knew that with it's severe limits, the Sound Interface Device has something special to offer. The composer of the music of this game did something marvelous.

He used arpeggio techniques to make the SID play chords

  • SID does not play polyphonic sound
  • Arpeggio gives the illusion of chords due to the rapid succession of notes played
  • Iconic music was spawned with Last Ninja
  • Unique arpeggio chords created on the SID are still seeked by those who were kids in that period
  • Others copied the technique and a cult music genre was born
  • People still create SID chords on emulated C64's to this day, since the machine is long gone in the anals of history

Background & history

Personal POV

  • Being brought up with acoustic instruments of all kind, I know how good and a great instruments should sound
  • I have perfect pitch
  • I can hear up to the 1/100 of a Hz if a instrument is in tune
  • It's annoying when instruments are out of tune for me.
  • That distuned instrument, sounds like a kakaphony of cats squealing making the played music horrific in my head
  • I came with a high level of raw musical talent enabling me to easily pickup all different kinds of acoustical instruments
  • Behind a piano, without any formal training, I could easily play a song in minutes with the chords and the lead tune in a good manner
  • I loved to play on the electric bass, so the bass track which I first compose in my head, when I play the piano, is played in sequence
  • I would then pickup one of the brass instruments (I love the Tenor Sax) and play the lead well in munutes too
  • All that was left was playing the chords on any synth or keyboard available (usually one of the Korg or Yamaha synths)
  • I can hear and mix the levels of instruments in my head
  • It's easy to remix a sound in my head without having to touch a mixing console
  • All of these talents combined give me good insights in music as a whole and computer (SID music then) as a detail
  • I can work on electrical equiment on the pcb level, something I picked up as a young kid
  • From the age of three I disassembled tube radios with expert precision, making me fluent in the disassembly and assembly of tube radios
  • I assembled them back in working order from the age of four, after complete disassebly!
  • This gives me great insight in the hardware level of electronics

Last Ninja+

  • I naturally dismantled my C64 again when I heard the game.
  • Why did the game sound that way from a hardware POV
  • What makes the IC tick
  • I've got the manuals of all the IC's
  • I had already replaced the PLA906114 Program Logic Array with a new one on a socked, with no qualms
  • The PLA9016114 got too hot in the tropics (max temp 70C) so it never lived long without a heat sink.
  • My PLA's were programmed by a friend of mine who was an expert in the programming field
  • The new PLA's came blank
  • I did all the extraction, socked soldering and other work myself

The answer was in the C64 hardware manual

  • SID does just 8 bit audio
  • has zero polyphony
  • a limited frequency range both low and high
  • has scratchy output (which I later learned to appreciate)
  • has monophonic, single channel analog output
  • is in actuality a fair sounding IC but far from great

The Yamaha 8 bit sound IC of that period was much better

Yamaha had less succes than the SID for a simple reason

Mass deployment

  • SID was everywhere!
  • C64 machines were sold like warm bread in the morning at the old baker
  • Mass deployment means much more software programmed for the IC
  • SID won on mass deplyment and lower price in comparison with the lead 8 bit Yamaha audio IC of that period
  • The ammount of games making use of the SID was staggering in comparision
  • Games drove the success of the SID to astronomical heights
  • I got used to the SID, later seeking it's sound when I transitioned to my Amiga A500 with

Paula

  • Paula is polyphonic with 16 bit (14 bits actually) sound
  • Paula sounds much cleaner
  • has 4 channels 0 1 2 3
  • hard panning of channels in the stereo analog output
  • more stability
  • more joy

Motivation for seeking SID after it was gone...

  • Simple
  • NOSTALGIA
  • We all have it
  • even kids do

Ode to SID

You've been great

Seek last Ninja on the C64 Archive sites for listening pleasure

#C64 #SID #Paula #Amiga #technology #mathematics #Physics #Chemistry #Linear #Algebra #directory #load #FDD #RetroComputing #music #Saxophone #Baritone #Piano #Korg #synth

Mar 7 at 1:59pmWeb
Show threadAlveus NosvilleMar 17

@blitter
>does just 8bit audio
No it's not, it's signal path is analog, it's just controlled by 8-bit signals, like the rest of the computer

>has zero polyphony
No it doesn't, it has 3 osciallators, each equiped with it's own Amp envelope. If you want to be a stickler, it'd technically still be just paraphony in proper Synth terms due to shared filter, however routing them through filter is optional so it's really not, it's 3 voices.

>The Yamaha 8 bit sound IC of that period was much better
You'll have to define a lot here, because AFAIK Yamaha did not have full voice ICs in 1982, when C64 first came out, it only started making devices with FM IC's which could act like like full voices in 1993, at which point a single IC could only do one voice at a time, so whether a single voice FM IC is better than C64's 3 voices, with a filter, with the integrated envelopes (which in Yamahas were handled by the central processor, I think), with 3 ring modulators AND with the option to turn osc 3 into an LFO and give it;s envelope to the filter is HIGHLY debatable, and that's not even mentioning the hacks found later, which allow it to play samples.

Also not to mention there are 2 versions of the SID 6581 and 8580, with 8580 being much cleaner, if without some of the OGs character, but that wouldn't fit the initial time period, by the time DX came out yes, Yamaha chips were probably better, but C64 was stuck with the same specs it released with, so it's not a fair comparison.

Other Than FM, they made clones of General Instruments' AY-3-8910, which was also an 3-voice but it had no filter and only one envelope, and Texas Instruments' SN76489, which could only do 3 square waves at 16 discrete volume levels, with no envelopes. The only advantage those had over SID was noise generation.

>Yamaha had less succes than the SID
I have literally no ide where that one came from. The original 1983 chips powered the DX7 synth, which singlehandedly ended the era of analog synthesis raign and usable synth UI for a number of years and the later chips were all over the place. OPL2 powered most IBM PC compatible sound cards, and their other chips made it to many consoles and arcade cabinets. Notably one of those - YM2151 - made it to a modern retro computer called Commander x16, which was literally made in Commodore's own image.

Yamaha wiped the floor with SID.

In fact I suspect that among the main reasons we never saw an officially released synthesizer using SIDs as it's voices, despite the fact SID was made with that in mind, as stated by the designers (and honestly even as logicly implied by the design itself), is the release of Yamaha DX7 year after C64 and the subsequent, aforementioned death of Analog Synths' prominence

>SID was everywhere
No. It only ever officially made it to C64 and C128, maybe some other offshoots I don't remember RN, but they'd all be based on the 64. The plans were there, but they went nowhere. I don't believe they even made it available to anyone else. If you think you heard it somewhere else - it's probably the AY chip - when the CPU has time to work the volumes itself it can sound a lot like SID with no filter on.

Also, of course I'm not the absolute authority on ANY of this. But I have dedicated a lot of time to studying Both the SID chip, and electronics history in regards to synths and personal computers, so I'm not too concerned about anyone verifying my claims.

Show threadBlitterMar 18

Thank you for the wonderful and detailed corrections I will boost the post so that the corrections are visible to everyone

@nosville22

Show threadAlveus NosvilleMar 25
@blitter fixed some grammar and filled a few missing words