4/25/15

Atari 2600 Soundfonts

 
The sound chip of the Atari 2600(& 7800) is a strange little beast. Soundtracks/music weren't really common in arcade games or the few other home consoles of the time so the TIA audio/visual chip of the 2600 was mainly intended to produce the simple bleep and bloop sound fx typical of the era.  As such very few 2600 games attempted to utilize background music even though it was possible.  A few notable games that I can think of offhand that utilize background music are Gyruss, Pitfall 2, and the impressive homebrew rendition of Super Mario Brothers called Princess Rescue (get it here).

In one of many confusing decisions Atari has made, their 7800 console also uses the same sound chip as the 2600.  It was originally intended just to preserve backwards compatibility with the still popular 2600 cartridges while they worked on developing a cheap version of their revered 5200/PC POKEY chip to be included in the cartridges.  The infamous video game crash happened right before the roll-out of the 7800 and the POKEY chip only appeared on 2 7800 games Ballblazer and Commando.  As it was directly competing with the NES and Sega Master System instead of the primitive consoles of the 2600 era the sound was a huge drawback even though the graphics are comparable (although the pixels are rectangular).

Despite being the most primitive of the chips I've covered thus far the reading and research I did for this soundpack actually took far longer than the entire process of making any of my other packs.  The main difference between this and my other soundpacks is the unorthodox tuning of the 2600's 32 available pitches isn't similar to any musical tuning or scale.  The best way to describe it would be a broken synthesizer which plays by its own rules that it hasn't even defined in a sensible way.  I almost didn't even download the set of samples from little-scale that I used because my memories of the sound of the 2600 wasn't very positive, but after listening to the sounds I was extremely surprised and found that sounds of the 2600 could be really useful in modern EDM style music.

I found a number of different sites that appeared to translate the pitches of the sounds to musical notes that inspired hope of an easy solution, but after trying various mappings none yielded usable results.  After much trial and error I realized that going about it my own way would be much more efficient.  I analyzed the pitches of all the samples and found that almost none closely matched notes and the same pitch numbers of the different sound types even had different pitches.  So I had to do a bit of math, their are 100 cents between notes so if a sample is off by 50 cents it's basically right between notes.  Given the unusual tuning I knew I had to make some compromises but still wanted the sounds to be in tune enough that they're usable with other sound-sources without having to manually detune everything else.  I roughly determined the mean and settled on a cutoff point of 30 cents above or below a note and removed any sample beyond that.  I also removed certain samples in the highest and lowest ranges where it was hard to determine the pitch. 

After all the subtractions I went through and tried to figure out a scale that would give me the most possible notes to use and ended up with F Melodic Minor scale (F, G, G#, A#, C, D, E).  I also removed sounds that were extremely similar and those which had too much noise to get an accurate pitch leaving 7 different sounds out of the 14 with around roughly a quarter to a third of the original samples per sound(The 05 and 12 sounds are really similar but offer different notes so I included both).  I also included soundfonts with all of the available notes within 30 cents (with the suffix all) in case anybody wants to try to use a different scale and another set of soundfonts with all of notes tuning tweaked to their respective notes and then spread across the entire keyboard (with the suffix full) to offer a better tuned but unauthentic set of sounds to use.  For "authentic" 2600 music with these you can use either the F Melodic Minor or All Available Notes sets with only 2 sounds playing at once at any given time.  If you intend to use drums I recommend downloading this sample pack from little-scale and perhaps sidechaining them to the bassline or even the melody.

Unsurprisingly given the nature of the chip their really aren't many 2600 vst emulations.  Their's a freeware emulation called hues2600 which can produce some pretty cool sounds but it doesn't seem very accurate to the hardware.  Theirs also Plogue Chipsounds which sounds much more authentic but I don't believe it's faithful to the tuning or limitations of the original hardware as I believe it's intended to give users a multitude of mostly accurate chipsounds rather than emulating the limitations of the different chips.

Download Links.

Atari 2600 Soundfonts 13 mb

Download Here

Atari 2600 Soundfont Bank 18 mb

Download Here


Notes.

Although little-scale offered 3 different envelope settings for all 14 audible soundtypes of the 2600 sounds I only used the "No-Env" set as it was the best for sustained sounds.  The two I didn't use are "Punchy Release" used for drum/fx type sounds and "Slow Attack" which can easily be simulated by adjusting the attack on your SF2 player of choice.  I opted not to provide a drum soundfont since little scale already put together a nice wav pack and the 2600 isn't really suited to emulate a full drumkit, but if their's demand for one I can give it a shot but I don't see it being of much use.  Thanks again to little-scale for providing the samples.  I highly recommend you check out both little-scale's blog and Atari Age for more info on the 2600 and much more.


1 comment:

  1. i played some doom midis with it, and boy did you nail it down! sounds just like it would n a 2600!

    ReplyDelete