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Play it again, SID

This is the unedited version of my Play it again, SID article, as published in issue 4 of Retro Gamer magazine.

One of the key features of the Commodore 64 was its dedicated sound synthesis chip. Known as SID (Sound Interface Device), the chip delivered high-quality, three channel sound. As Adam Dawes reveals, this small piece of silicon had quite a future ahead of it.

The SID chip was designed in 1981 by Bob Yannes, the Commodore 64's systems architect. At a glance, the specifications of the chip look rather basic. The SID had three voices, and so could play three different notes simultaneously. Four different types of sound were available: a sawtooth wave, triangle wave, pulse wave and white noise. Each voice could independently choose which type of sound to play.

On top of this it was possible to apply filters to the voices to change the way they sounded. Properly applied, this allowed the basic sound types listed above to produce much more varied notes, more like a music synthesizer. The chip had both analogue and digital components, and the analogue parts of the chip allowed a far greater variety of sounds to be produced than would otherwise be possible.

Compared to the sound hardware we are used to today, this may sound quite basic. But in the early 1980s this was impressive stuff, especially considering the size and budget constraints that governed the SID's design. Even so, one cannot help but wonder whether Bob Yannes had any idea of the real potential of his chip, or of the uses to which it would be put over the coming years.

The C64 was not the only 8-bit computer that could produce sound of course. The main platforms that were in competition at the time were the Sinclair ZX Spectrum, the Amstrad CPC computers and the Acorn BBC.

The original Spectrum computers as we all know could only produce a simple monotone beep, so these were never going to compete with the aural capabilities of the SID chip. The Amstrad computers (and also the later 128K versions of the Spectrum) were fitted with a General Instruments AY-3-8912 sound chip, and the BBC with a Texas Instruments SN76489 chip. Both of these chips were capable of producing three channels of sound plus an additional channel of white noise.

While some excellent music was produced for these chips (some of which can still be heard in MP3 format on the internet), the overall sound was never as rich or as complex as that produced by the more flexible SID chip and they never received the same level of attention.

C64 music in the beginning

Initially the music and sound effects produced by the C64 were also fairly basic. The SID was used mainly for simple sound effects, and the music was little more than simple chords and tunes using the unmodified sound types described above. Those of you with an emulator to hand might like to take a listen to the music for the game Falcon Patrol for an example that is typical of this era of the C64's music evolution.

Things continued in this vein up until around 1985, when something quite unexpected happened. A new breed of SID musicians released wave after wave of innovative, high quality and fantastic sounding music on an unsuspecting public. For many of us that were there at the time, things have never been quite the same since.

One of the first and most famous composers was a man by the name of Rob Hubbard. Hubbard recalls being unimpressed with the music produced by the home computers at the time, as most of it was out-of-tune or simply sounded bad. After trying unsuccessfully to sell his own software he decided to focus on writing music for other people's games.

One of his first pieces of commercially published C64 music was written for Thing On A Spring, a platform game published by Gremlin Graphics. Gary Penn, staff writer of the magazine Zzap!64, said of the game in their August 1985 review, "This game has incredible instant appeal due to the exceptional piece of music (I've never heard anything so marvellous on the 64)�" Julian Rignall continued the review with "The sound is unbelievable, I won't describe it but just wait until you hear it; words fail." The sound for the game was awarded 98%, with the comment, "The London Symphony Orchestra might just sound better."

And with this, the C64 music scene was born.

Several other musicians were also working on producing high quality music for the SID chip at around this time. Names that are now famous to thousands of fans include (among numerous others) Martin Galway, Ben Daglish, David Whittaker and Jeroen Tel. Many of these musicians also wrote their own assembly-language music players in order to generate their music.

The musicians employed many tricks to improve their music so that it sounded like it was beyond the technical limitations of the SID chip. One of these tricks is to use "arpeggio" sounds, whereby the notes of a chord are played vary rapidly in succession. This results in what sounds like a chord, but using only one of the three available voices.

Drums were created by using the white noise sounds, often with volume effects applied to make them sound more realistic. Clever layering of the melody, drums and bass lines were often employed to give the impression that more than three voices were in use.

This resulted in a distinctive, synthetic, electronic sound that fit perfectly with the popular mainstream music of the 1980s. Over the following seven or eight years, C64 music enthusiasts were treated to one fantastic melody after another. Every month seemed to bring something new in a way computer game music has never since managed to repeat.

The coders and hackers at the time were well aware of how good the music being produced was. Hundreds of demos were released with music "ripped" from games so that it could play in the background of the demo. The POKEs required to play the music (along with all of the sub-tunes that the game would use as it progressed) regularly featured in magazines so that people could listen to the music outside of the games themselves.

The games-buying public were also well aware of the quality of these tunes. There are anecdotal tales of games being bought quicker than they could be put on the shelves simply because a new Rob Hubbard tune appeared within. The quality of the game often didn't matter; in many cases the music was commissioned and composed before the game had even been designed. The music within each game became a significant factor as to how successful the title might become.

Sampled sounds

One of the technical tricks that the SID was coaxed into performing was that of playing sampled sound. This certainly wasn't on the feature list when it was designed, but some clever programmers took advantage of the simple fact that the SID made a clicking noise when its volume level was modified. By very rapidly changing the volume level it was possible to produce some low quality (but perfectly reasonable) 4-bit sampled sounds.

One of the earliest and most memorable uses for this was in the game Impossible Mission, released by Epyx in 1984. When the game started, an evil voice addressed you from within your TV, saying, "Another visitor. Stay awhile � stay forever!" It set the scene perfectly, along with a number of other samples that featured during the game. Ghostbusters also employed sampled sounds to good effect.

Initially however the amount of work the CPU was required to perform in order to play these sounds meant that little else happened while the samples were playing. The action would freeze until the speech had finished. This problem was solved later on and sampled sound became more common, used both for sound effects (I, Ball and Mega Apocalypse both featured samples in this way) and also in some of the later pieces of music.

Sampled sounds were particularly well suited to producing drum effects. Due to the nature of percussive sounds, the low quality samples rarely tended to be noticeable. Using this trick to play samples also effectively created a fourth sound channel (none of the other three channels were required in order for samples to be played), giving the musicians a whole new set of things to try.

There are many excellent pieces of music that use sampled sounds for drums, speech and other effects. The first to be released was Martin Galway's music for Arkanoid, published by Imagine in 1987. Galway admits that he didn't actually have any sampled drum sounds so the drums used in this piece of music were created manually (he describes them as "a collage of farts and burps").

The technique was very much refined over the coming months and years, however. Worthy of particular mention are Savage and Turbo Outrun (both by Jeroen Tel and the Maniacs of Noise) and Combat School (again by Martin Galway) which all make excellent use of sampled sound.

Towards the present day

Towards the latter part of the 1980s, the C64 and the other 8-bit machines found that they had to compete with a range of much more powerful computer and console systems. The likes of the Amiga, Atari ST, Megadrive and SNES were making it clear that the days of the 8-bit computer were numbered. Whilst they battled on valiantly throughout much of the 1990s, the popularity was unquestionably reduced compared to the years gone by.

As the viability of publishing software on the C64 decreased, the amount of new music produced for the platform naturally reduced too as the software companies switched their attention to the 16-bit systems. Many of the SID musicians moved to these new platforms.

Despite the enhanced capabilities of the new computers, however, the music was never quite as good as it used to be on the C64. The Amiga for example, despite its powerful digital sample-based sound chip named Paula, produced quite different sounds to those of the C64. Some excellent music was produced for the Amiga but it never had quite the same impact as the SID music had achieved back in the 1980s.

And so the C64 and the SID chip slowly faded into history, but the music lived on in the minds of many thousands of people, gone but not forgotten.

This is far from the end of the story, of course. A thriving community of remixers and performers have embraced the SID tunes of the past in some surprising ways. But first let's look back to where it all started.

As far back as 1986, a company called Mupados released via the W. H. Smith chain of shops a cassette tape called Datahits. This tape contained the first remixes of C64 music, containing enhanced versions of the tunes from Rambo, Never Ending Story, Ghostbusters, Crazy Comets and Hyper Sports. The music was still fairly similar to the original (the C64 still provided all of the melody) but was in stereo and had realistic sampled drum tracks overlaid onto the music.

Another piece of music on similar lines was provided on a cassette given away with Zzap!64 magazine in June 1987. The cassette, called "The Zzap Sampler," contained a number of game demos on side 1, and a fully remixed version of the Sanxion loading tune on side 2 entitled "Thalamusic." This was rearranged by Hubbard himself using top-of-the-range keyboards and drum machines, and it was extremely popular.

Remixes of the C64 classics have continued to be made right up until today. Many thousands of them can be found on the internet, all in MP3 format and available to download for free. The original songs have been remixed in more ways than can be imagined, from hardcore techno versions to "boy band" mixes complete with harmonious lyrics.

Not all of these are just sequenced on computers, either - a number of bands have formed to play music inspired by the C64. One such band is Machinae Supremacy, whose version of Chris Huelsbeck's Great Giana Sisters is definitely worth a listen (as are the other MP3s on their website, http://www.machinaesupremacy.com). But more on live performances later on�

Back In Time

One of the first people to start giving serious thought to reworking the SID classics was Chris Abbott. In 1998 he produced the first of what was to become a series of CDs entitled "Back In Time." The CD, sold via his web site C64Audio.com, contained 15 completely new remixes, several of which were worked on by Hubbard himself (which was quite an achievement as Hubbard had all but completely disappeared from the public eye and from writing music for computer games in the years before this). All of the tunes on the CD were licensed, with royalties paid to the original artists.

"It was a CD I wanted to see, but no one else was going to make it happen," says Chris. "They were all waiting for the composers to release CDs themselves." Were the composers supportive of the idea? "They reacted with various combinations of suspicion (of legal and monetary matters), help and scepticism, and the occasional 'you go, girl'". The CD was a success however (to Chris's relief), and has now completely sold out. This disc will no doubt be a retro collectors item itself in years to come.

Since this time, many more CDs have been produced, both by Chris and by other people with similar interests. A number of these are straightforward remix CDs, though they also include more original titles such as "Sidologie" (a CD by Marcel Donn� containing 11 SID tunes remixed in the style of Jean Michel Jarre and Vangelis) and "Project Galway" (a double CD of songs recorded directly from Martin Galway's own SID chip - each SID chip sounded slightly different so for purists this is the only way to hear the songs as they were originally intended to be heard).

A number of future productions are also in development at C64Audio, one of which is a large collection of polyphonic ringtones for suitably capable mobile phones. These should be available some time during the summer. Information about these and all of the CDs can be found on the web site (see the Resources section for details).

The most startling and unique thing to come from the organisation, however, has to be the Back In Time Live concerts. Not satisfied with listening to music on CDs, Chris decided to organise a string of live concerts, with the hits we know and love being performed by bands on stage, in front of our very eyes.

The first of these was held in a night-club Birmingham in May 2001 and was very popular with those that attended. Many of the celebrities of the C64 era were present; in addition to a large array of musicians there were well known faces from the coding and publishing world (the event included a light show by Jeff "Yak" Minter).

Chris Abbott again: "An 8-bit gig worked in Finland, so I figured it could work here. The original idea was cheap dance gigs for students though, not the fan-driven celebrity performance monolith it's become."

Since then there have been a total of six Back In Time Live concerts, the most recent of which was a spectacular day held at The Brighton Centre. Several hundred people attended the event, which was split into two parts. During the day was a chance for the visitors to show their prowess on a variety of classic C64 games and mingle with the celebrities and other fans, before the concert itself started in the evening.

The performance started with a newly formed group, Stuck In D'80s, comprising Mark "madfiddler" Knight, Ben Daglish, Marcel Donn�, Reyn Ouwehand and Andreas Wallstrom. This was followed by a one-off performance, "Rob Hubbard Unplugged," during which the most famous of all the SID composers played some of his classic tunes.

This was followed by a lively set by Press Play On Tape, one of the most prolific of the C64-inspired bands. Originating in Denmark, the group's line up is Andre Tischer Poulsen and Theo Engell-Nielsen on keyboards, Uffe Friis Lichtenberg on bass, Jesper Holm Olsen and Martin Koch on guitar and S�ren Trautner Madsen on the drums. Complete with a large video screen showing the games that they were covering, these guys were very impressive to watch and even managed to fill the dance floor.

The climax of the event was a combined performance by Stuck In D'80s, Press Play On Tape and Rob Hubbard playing a fantastic rendition of Monty On The Run. I suspect there cannot be many violinists that could play this fast and complex melody as well as Mark Knight managed to. A DVD video of the day is planned for release later in the year.

If this sounds interesting then don't worry, as the next Back In Time Live concert is in the planning stages right now. We asked Chris for the details. "Well, it's a live concert with seven acts, in three parts. And we're still looking for a theatre man enough. Stuck in D'80s and Press Play on Tape will headline it. Sponsorship welcomed!" The event should take place in London this September.

Sidplay and the HVSC

If that all sounds a bit too much though, and you simply want to remind yourself of how the C64 itself sounded back in its prime, then you may be interested to know about a free program called Sidplay2.

A very clever piece of programming, this utility emulates both the C64 CPU and also the SID chip. This allows the original assembly-language sound routines and music data to be extracted from the memory of a C64 and played on any PC. The reproduction isn't entirely perfect, but it's very close and will bring back a lot of memories to anyone that remembers the music the first time around.

There's no need to worry about how to get hold of the music, either. An online archive called the High Voltage SID Collection can help out there. Set up in 1996, this project aims to offer every single piece of music ever created for the SID chip. While they still have some way to go to get absolutely everything, they have a substantial amount of material already available including pretty much every one of the well-known songs ever created.

You can read more about the HVSC later in this article, and all the details of how to obtain Sidplay2 and the HVSC archive can be found in the Resources section.

It's even possible to create new SID music today - a piece of software called GoatTracker (http://covertbitops.c64.org/) allows C64-compatible music to be created. A variety of new compositions appear each year, most of which are then added to the HVSC.

Unusual SID setups

And what of the SID chip itself? They're obviously no longer being manufactured but there are many of them already in existence (over 30 million C64s were sold), and they're popping up in some surprising places.

The first of these is a piece of hardware called HardSID (http://www.hardsid.com/). This is a PCI sound card (compatible with Windows and Mac OS X) with a genuine SID chip on board. The card can be used with Playsid2 and also a number of C64 emulators to provide real playback of sound through the original hardware. An enhanced version, HardSID Quattro, has four SID chips onboard to allow a total of 12 channels of SID sound to be played.

Another piece of hardware, Catweasle MK3 (http://www.jschoenfeld.com/) allows for a SID chip to be mounted and used in the same way as the HardSID card.

Finally we have SidStation (http://www.sidstation.com/), a complete MIDI synthesiser based on the SID chip. Some impressive examples of the device in action are available from the web site.

With the amount of dedication and enthusiasm that still exists in the world of the SID chip, and with the advancements of hardware and emulation technology, it looks like the music - and even the SID itself - is set to live on for many years to come.


Many thanks to Chris Abbott at C64Audio.com and Peter Sand�n at the High Voltage SID Collection for their assistance with this article.

Where are they now?

Most of the musicians from the C64 era have drifted (many by choice) out of the public eye, so we thought we would track down where they had gone. This is what we found:

Ben Daglish

C64 works include: Ark Pandora, Deflektor, Gauntlet, Kettle, Krakout, Trap.

Now performing with the folk/rock group Loscoe State Opera, producing/directing soundtracks for theatre productions and running an Internet Service Provider.

Martin Galway

C64 works include: Comic Bakery, Miami Vice, Ocean Loader, Rambo, Wizball.

Now working in Audio Production for Microsoft Game Studios in the USA (was Audio Director for the recent game Freelancer).

Fred Gray

C64 works include: Breakthru, Enigma Force, Frankie Goes to Hollywood, Mutants.

Now teaching nursing students to use computers.

Rob Hubbard

C64 works include: Auf Wiedersehen Monty, Commando, Delta, Sanxion, Thing on a Spring, Thrust.

Worked as audio technical director at Electronic Arts in the USA, before recently leaving to work as musical director on a cruise ship.

Richard Joseph

C64 works include: Barbarian, Defender of the Crown, Rimrunner, Sacred Armour of Antiriad.

Working as audio director at Elixir Studios. Recent work includes audio direction for the game Republic: The Revolution.

Jeroen Tel

C64 works include: Cybernoid I and II, Hawkeye, Savage, Turbo Outrun.

Still making music with the Maniacs of Noise, information and downloads at http://www.maniacsofnoise.nl.

David Whittaker

C64 works include: BMX Simulator, Feud, Glider Rider, IO, Street Surfer.

Working and composing computer game music at Jester Interactive.

Top 10 C64 Game Tunes

The following top 10 pieces of C64 game music were voted for by the readers of the remix64.com message board and the comp.sys.cbm newsgroup.

10. The Last Ninja (Ben Daglish)
9. Mega Apocalypse (Rob Hubbard)
8. Thrust (Rob Hubbard)
7. Turbo Outrun (Jeroen Tel/Maniacs of Noise)
6. Rambo (Martin Galway)
5. Cybernoid (Jeroen Tel/Maniacs of Noise)
4. Trap (Ben Daglish)
3. Parallax (Martin Galway)
2. Sanxion (Rob Hubbard)
1. Delta (Rob Hubbard)


Retro Gamer tracked down Peter Sand�n, one of the maintainers of the High Voltage SID Collection, in order to find out some more about the project.

How did the HVSC get started? Whose idea was it to create a definitive archive of all the original C64 music?

The HVSC project started in May 1996 when "The Shark" decided to merge many SID collections available on the internet into one big collection. The previous SID collections contained many bugged SIDs, repeats, and inaccurate credits - not to mention being highly disorganised. A few months later he added two more members to the team, Michael Schwendt and "Rambones". As they merged the collections, they began to realise that many famous SIDs were missing. This led the HVSC Crew and many others to begin searching various C64 software archives for more SIDs to rip.

Due to this effort the collection began to grow at an enormous rate, and the members grew with the collection. As we progressed we noticed that many inconsistencies and questions started to surface. For example, we would find a piece of music credited to a famous composer yet the style of the music was completely different from his normal style.

One sure way of solving these mysteries was to contact the original composers. Over time we gradually tracked several of them down and received a tremendous amount of information.

Have you had any problems getting hold of the music to be included in the HVSC, such as copyright problems, technical problems (software protection, etc.), or simply finding a source for a tune?

Copyright problems... Yes, but only minor ones. Some composers were unhappy at first but we eventually worked out a better relationship; most of them are really happy to see that their old work is being preserved, and they often enjoy hearing their work again after all this time. We are fortunate in that most of the collection is abandonware.

There have been some technical problems however. I remember a few years ago when Simon White introduced Sidplay2 to us, a lot of tunes stopped working. The fact was that Simon White finally gave us a cycle accurate player, and the new goal was to make all rips compatible with a real C64. As time goes by, Simon improves the C64 compatibility in Sidplay2, and we have to fix some more tunes...

Other ripping difficulties have mostly been from really old games where the coders made the music themselves and spread the code all over the memory. This takes an enormous amount of time and skill to successfully rip. When it comes to demo tunes sometimes a tune was badly ripped from another production and picked up bugs or corruption on the way, so when we rip from the demo, it's impossible to make a 100% working rip.

Even some original games had tunes that bugged out after a while. Most of these have been fixed by correcting the code or modifying the music data, and were then verified by the author to be a 100% accurate version.

How and where do you get new material for each of the new revisions of the HVSC?

Getting material for the collection is not hard. There are plenty of tunes missing, and more tunes are being released all the time. We contact the composers, and sometimes get hold of their disks, and can provide the collection with long lost tunes, and even unreleased tunes.

Gamebase64 (http://www.gamebase64.com) has a database with C64 games, and from that database we know which games we still have to rip the music from. I also have several CDs of C64 disks. It's harder to get people to help out ripping so that we can continue providing the best collection available so if anyone out there has the skills to rip tunes and wants to help out, please get in touch with us.

How many people work on the HVSC? How much effort is involved in each new revision?

Currently there are 12 members of the crew, but we also get some help from external contributors. It's hard to say how much work that we put into each update, because there are a lot of steps before we can release each one.

First of all it takes time to rip the tunes, and check that they're working on both Sidplay2 and on a real C64. Then we try to verify credits with the authors (even published games sometimes had incorrect credits.) Next we have a guy who builds the update script, and put all our newly collected tunes into the update. After this we test the update on various platforms to be sure it's working properly on them all. Finally our STIL (SID Tune Information List) administrator compiles an updated STIL.txt file.

What can we expect in the future for HVSC?

We've released some quite big updates recently to get rid of our backlog of SIDs. We had around 4,000 unreleased tunes lying around.

After the next update our unreleased archive will be empty and we'll need to rip new tunes for all forthcoming updates, so it might take a while longer between the updates after the next one and they might be smaller as well. I'm quite sure we'll pass the 30,000 SIDs mark within the next few years.

Are the crew involved with any other C64 related projects?

Yes, I'm also running the composers page at: http://composers.c64.org/. Stephan has the Demo Dungeon at http://www.demodungeon.com/. Chris Abbott is active on the C64Audio web site (see main article) and has arranged the "Back in Time Live" events with a reunion of some of the most legendary C64 composers, and live performances from them as well.


Want to find more information? Try some of these web sites.

C64 Audio


The home of some of the greatest C64 remake CDs, released over the last few years.



An excellent resource for C64 and Amiga music remakes. The discussion board is well worth a look too.



A collection of thousands of freely downloadable remixes of many classic C64 tunes in MP3 format.



The web site for the Sidplay program, available for Windows and Linux. Windows users may also like to take a look at Sidplay2/w at http://www.gsldata.se/c64/spw/, which offers an easy-to-use GUI as well as the SID player itself. A Mac version of the original Sidplay is also available at http://stud1.tuwien.ac.at/~e9426444/sidplay/.

High Voltage SID Collection


An ongoing project to archive as much original C64 music as possible (currently over 25,000 tunes). Can be played using Sidplay.

If you have any comments or suggestions regarding this article, please don't hesitate to contact me.

This article is copyright © Adam Dawes, 2004.
It may not be copied or redistributed without my express written permission.