Talk:MOS Technology 6581

Proposed article move
This article should be moved to MOS Technology 6581 for greater orthogonality with other MOS Technology integrated circuit articles, such as MOS Technology 6522 and MOS Technology 6532. Note that these are named by their numeric designations and not their titles (VIA and RIOT, respectively). This should be made consistent. Crotalus horridus 19:32, 11 December 2005 (UTC)


 * OK with me, but IF AND ONLY IF you change ALL the links on ALL pages that in turn link here. Thats a lot of work see. Nixdorf 19:47, 11 December 2005 (UTC)


 * I prefer it the way it is now. Mirror Vax 23:15, 11 December 2005 (UTC)

Fixed in...?
Does anybody really know at which actual hardware revision the pop-on-volume-change "bug" was fixed? I'm not sure, but I think the story is that while C64 C model has 8580s, it's not at all related to the sample volume issues, because every C64 C I've used seem to play samples just fine and this issue cropped up after the C generation. I have both a C64C and a C64G, and the C can play digital samples just fine, while the G has pretty quiet samples - so it was "fixed" in either the G (which seems to be my recollection) or some slightly earlier C64 hardware iteration. --wwwwolf (barks/growls) 15:45, 14 January 2006 (UTC)
 * it was fixed in the (all) 8580. you can still play samples using other techniques (PWM for example) or even using the good old volume-register banging though, if you create an artificial voltage leak by playing something on the other voices. — Preceding unsigned comment added by 62.143.153.84 (talk) 17:19, 25 July 2012 (UTC)

Phrasing In Revisions Section
"This probably means that the R1 was the first round of chips and R2 actually the second mask produced." What exactly does the author mean 'and R2 actually the second mask produced."? I was going to reword it, but I don't understand what he/she was trying to communicate with this sentence. JousterL 00:54, 08 November 2006 (UTC)

Invalid Rationale?
The following statement:

"A HMOS-II version of the 6581 was produced, the 6582. Like the 8580, this chip used 5 volts and 9 volts for its power supplies. It was never shipped in new Commodore 64s, however due to its lower voltage requirement,"

Appears to be an invalid rationale for the 6582 not being shipped in new Commodore 64s, since 8580's were shipped in C models, and these are 9V HMOS-II devices. I think this statement should be removed because it's speculative. — Preceding unsigned comment added by 24.123.112.118 (talk) 18:08, 12 March 2007 (UTC)


 * the 6582 was produced for the C65 (yes 65), and was indeed never shipped or used in production units. its also not a new chip at all - when you open up a 6582 the DIE says "8580" :) — Preceding unsigned comment added by 62.143.153.84 (talk) 17:20, 25 July 2012 (UTC)

Ring Modulation
It seems to me (tho it is equivalent) that the SID did ring modulation by multiplying the values of the oscilators instead of convolving their spectra as this is far far cheaper to implement. In simple terms, in a ring modulator the output of one oscilator acts as a volume control for another oscilator. There is really no need to work in the frequency domain and it seems highly unlikely that the SID (or anything in those times bar supercomputers) was capable of spectral analysis. — Preceding unsigned comment added by 83.87.224.111 (talk) 12:37, 21 December 2007 (UTC)


 * That is incorrect. Ring modulation on the SID is actually done by setting the output of one oscillator to the logical XOR of the output of said oscillator and the MSB (most significant bit) of another oscillator's internal accumulator value. In addition, ring modulation on the SID can only be enabled with the triangle wave, so the output of ring modulation will always be a triangle wave ring modulated with a square wave (no matter the pulse width value, as the wave is coming from an accumulator, not a waveform generator's output). TreeNamedUser (talk) 04:04, 17 February 2021 (UTC)

Mention The Postal Service
Under the "Conventional Music" section, we could include a note about the The Postal Service. Something like: "Although The Postal Service does not use any samples of SID music, many of their tracks have a sound similar to SID sound." MatrixFrog (talk) 05:47, 11 January 2010 (UTC)

Cleaned up "Conventional music" section
Hi. That section was tagged for over 4 years as lacking references. So I removed all entries that weren't immediately verifiable via either a still-alive link or its own article and references therein. The unreferenced section tag has been removed. Anyone who misses the old content can please add it back with some kind of verifiability or reliable source to collaborate. --Ds13 (talk) 02:16, 29 December 2011 (UTC)

32 voices one oscillator?

 * "...the SID was originally designed to have 32 independent voices, sharing a common oscillator."

This doesn't make sense to me, and seems like a misreading or misquote to me. What does the source actually say? Were they supposed to share a common noise generator, or maybe an LFO modulator? Or possibly high frequency multiplexing sharing a common operator amongst all voices? I don't understand how independent voices can share the same oscillator. - Rainwarrior (talk) 03:54, 10 December 2012 (UTC)


 * The question of what exactly the original source says is definitely a valid question, but I don't believe this is an absurd a claim as it might seem on face value. I believe that using frequency dividers, one high-speed oscillator (probably running at higher than audio frequency so that all the needed musical note frequencies can be divided evenly) can drive multiple voices that can each play different notes (and potentially even different waveforms).  --Dan Harkless (talk) 18:07, 17 October 2016 (UTC)

I looked at the book (On the Edge) and read the passage, it is clear the design was a work in progress. The intent was to use a wavetable lookup approach and the circuit would be multiplexed to create the 32 voices. Now this is me talking (the anonymous person who added this paragraph) and from experience designing audio circuitry, but back then creating an ASIC that would do viable wavetable 32 voice synthesis would have been ambitious. Would the wavetables exist in the C64's main memory? This would be a dma burden. Would they exist in the fabric of the sound chip itself? This would require lots of real estate. Wavetables... are we talking 4 bits per sample, 32 samples? That's 128 bits of data per voice or 4096 total for even a low quality solution. Then there's the problem of stepping through the wavetables, so you'd need counters to keep track of the index into each table (32 of them) and for each counter you'd need a step value to add to each counter, and these need fractional values after the decimal point. 5 bit pointer with 15 bits fractional part would probably be enough, so 40 bits per channel times 32 = 1280 bits. Then you've got to mix all the samples together and convert to analog... All this is really really ambitious for the task at hand. Hence they compromized and cut + pasted a simpler circuit 3x. Good judgement call IMO. 104.179.121.40 (talk) 23:06, 17 January 2022 (UTC)


 * this whole story isn't implausible - the DOC chip used in Yannes' later work (Mirage, ESQ-1) is effectively this. Agrecascino (talk) 02:54, 12 March 2022 (UTC)

Removed link overkill
I have removed the following list of links, which is swamping the article, is more like advertising, and seems to not comply with External links. — billinghurst  sDrewth  08:07, 21 August 2013 (UTC) Hardware
 * SIDblaster/USB - HardSID compatible DIY SID-dongle
 * SID Blaster/ZX - sound card for ZX-Spectrum
 * Prophet 64 "The future of SID music"
 * Home of MIDIbox SID
 * Elektron Sidstation
 * Elektron Monomachine
 * HardSID
 * HyperSID
 * thrashbarg's MOS-ATmega8 project
 * Example of interfacing a SID with an Atmel ATmega168
 * PlaySoniq - MSX cartridge with SID on it -among others-)

Software / emulators
 * Tiny'R'Sid - cross-platform RSID player based on Adobe Flash 10
 * HVMEC - This collection contains possibly all available C64 programs that were made in the past for creating music
 * ReSID - Dag Lem's ReSID SID emulator
 * ReSID filter distortion simulation - Antti Lankila's patch to ReSID to vastly improve the analog filtering emulation, among other things.
 * SidTool 2 - Multi SID emulator frontend for Windows
 * PlaySID - SID emulator for Amiga
 * JAM - JAM multiformat player with SID plugin for Atari TOS compatible machines
 * PlaySID - SID emulator for Atari ST/E/TT/Falcon
 * FlaySID - SID emulator for Atari Falcon
 * PSID64 — Converts SID files to executables for playing SID music on a real C64
 * SIDplay2 - SID emulator for Windows and Linux
 * Java SIDplay2 - SID emulator for Java platforms
 * SIDPLAY - SID emulator for Mac OS X
 * JSIDplay Java based SID player (with HVSC on-line)
 * ACID64 Player - Commodore 64 Music Player for Windows
 * unknown64 - a VSTi Commodore64/SID Chip emulator
 * SE64 - Commodore64/SID Chip inspired VSTi
 * quadraSID - a commercial VST-SID Chip emulator
 * Chipamp - Winamp plug-in bundle compiled by OverClocked ReMix allowing playback of over 40 chiptune and tracker formats
 * foo_sid - SID file plugin for foobar2000
 * Rockbox plays SID files
 * SIDplay2/w - SID Player for Windows (Win32 GUI front-end for SIDplay2)
 * The Audacious Media Player also plays SID files
 * SIDPlayer - SID player for BeOS and Linux
 * Sid Player Sid Player for iPhone 2G, 3G / iPod Touch 1. & 2.Gen
 * Sid Player Pro a special Sid Player of Sid Player with more features
 * Chipsounds - VST/AU/RTAS - Emulations of 2A03, AY-3-8910, DMG-CPU, P8244, POKEY, SID, SN76489, TIA, UVI and the VIC-I.
 * SIDizer - Advanced emulation of SID chip (commercial VST/Standalone)

Music
 * The High Voltage SID Collection – The SID music preservation project
 * 6581-8580 Project (SOASC) - The entire HVSC#49 recorded on three types of SID chips with real Commodore 64 computers Also included are all the .sid files from HVSC.
 * Paulie's Ocean SID Page - Site discussing Ocean's SID player, the Ocean Loading Music and source code for Ocean's SID player.
 * Compute's Gazette SID Collection
 * remix.kwed.org – a collection of over 2100 C64 SID remixes (as of May 1, 2008)
 * Remix64.com – Community for C64 SID and Amiga music remixes
 * SLAY Radio – Radio station that features remixed Commodore 64 music and live shows
 * Machinae Supremacy The Origin Of SID Metal
 * PRESS PLAY ON TAPE The C64 revival band, PRESS PLAY ON TAPE

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Lead rewrite
The name of the article is "MOS Technology 6582", but that number is not mentioned in the lead. Very confusing/misleading title. Christian75 (talk) 14:04, 29 November 2018 (UTC)
 * The title was changed on 15 October 2018 from MOS Technology SID to MOS Technology 6582, with an edit summary stating "The move was proposed for better orthogonality with other MOS chips."
 * Presumaby "better orthogonality" refers to the December 2005 proposal to move to MOS Technology 6581. Clearly there is no support for "6582", so either the title should revert back to the longstanding MOS Technology SID or moved to the long-proposed MOS Technology 6581. Eric Hallahan thinks this page should be renamed to "MOS Technology 6581" to match the original model number. I can go either way, so I'll wait a bit to see whether anyone else has an opinion before moving the page. – wbm1058 (talk) 20:02, 12 January 2019 (UTC)

"B.Y. TIM"
http://sid.kubarth.com/sid_dies.html

On this weblink, there are microphotos of markings on the MOS 6581R3 die, including one odd marking that says "B.Y. TIM". Searching this phrase on Google returns me nothing relevant to the 6581, so the meaning of this marking (whether it was the initials of someone or something else) is a mystery to me. Not even the C64 Wiki has any info about this marking, but it does have an article on a piece of software dubbed TIM (for "Terminal Interface Monitor") used on CBM and CBM-II computers. However, I cannot see a connection between this TIM and the "TIM" in the 6581R3 markings. Any info on this mysterious "B.Y. TIM" marking that could be mentioned on this article? &#x200b;‑‑🌀⁠SilSinnAL982100⁠💬 02:20, 28 March 2019 (UTC)


 * I know that "B.Y." means Bob Yannes, the person who designed the SID chip. I do not, however, know what "TIM" means. TreeNamedUser (talk) 04:06, 17 February 2021 (UTC)