Propeller turned into chiptune player with a software SID

If there wasn’t reason enough to love the Parallax Propeller, now you can listen to chiptunes with your own pocket SID audio player.

This chiptune audio player uses the very unusual and very cool eight-core Parallax Propeller microcontroller. After soldering a few caps and resistors to a Propeller dev board to allow for audio out, the only thing necessary to play SID music files is a bit of code and an SD card breakout.

The key piece of code for this build would be the SIDcog object written by [Johannes Ahlebrand] this piece of code turns one of the eight cores in the Propeller into a virtual version of the classic Commodore 64 sound chip.

Since the SIDcog object only takes up one core on the eight core Propeller, it could be possible to turn this SID player into an all-inclusive chiptune audio source; the addition of an Atari POKEY or FM synthesis cog would allow for just about any conceivable chiptune sound to be carried around in a pocket.

No Hackaday post about chiptunes or SIDs would be complete without an audio demo, so you can check out the Propeller-powered SID after the break.

10 thoughts on “Propeller turned into chiptune player with a software SID

  1. Nice work. Adding other “chips” to the mix would be cool, but the first thing that comes to mind is a midi enabled device with 8 sid chips. Imagine the amazingly lush chiptunes that could be made with that many sid chips working in concert. Please oh please somebody do that.

  2. The SIDcog driver object used in this uses a single “cog” (There are 8 total). There is NO REASON why this project couldn’t be easily expanded to do stereo sid, or more. It’s a matter of adding another copy of the object in another cog. I’m working on getting the AXELF.MUS stereo files working on a similar project.

    1. The only limiting factor here, I think is program space — assuming good code re-use (or small enough programs running in each cog) — and midi interface (or any external streaming interface — or small enough loops to fit into memory for each cog), methinks you are correct.

    1. Who uses Arduino anyway, when you can just use AVR?

      As for the propeller, it’s an amazing piece of hardware, and I was *VERY* excited about it when it first came out — now, not so much — no open source tool chain (that works decently anyway, there are a couple alpha-versions floating around) — and it makes you write code for it in this god awful language that’s like pulling teeth to code in.

      Not to mention when you first turn it on (using the recommended hardware configuration / setup from the user guide) it takes almost a full second before it starts to actually do anything (i.e. execute your program — as during that second, it’s loading your program from an external serial rom chip into memory) — doesn’t seem like a big deal at first — but it kind of is… and excludes it from being useful as support hardware in another project, etc…

  3. There are several synths that use the prop and sid cog for the sound already, including a tut for one at gadget gangster. My prop based personal micro computer has a dmp file loader to play old chip tunes as well.

    1. I bet it could, unless there is something crazy about that chip that would be hard to emulate? The thing runs at ~20 MIPs per cog and has a decent amount of ram (Of the top of my head, I think it’s 32k total? That counts the program as well, it’s not a Harvard architecture chip).

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