Posts Tagged ‘RetroCade Synth’

“Really Dumb” MIDI Monitor For RetroCade

Monday, February 10th, 2014


Forum member Offroad recently hit us up with an example project, which is  based on the Papilio Pro and the RetroCade Synth. He’s calling it the Really Dumb MIDI Monitor.  This deserves a bit of explanation:

For starters, Offroad explains what he means by the term, “really dumb meaning: All the fun stuff like printf(“%02c”, byte) happens in RTL state machines…”

The project includes a simple MIDI parser for note on-/off messages. It remembers the state of all keys (all channels are combined, “omni mode”). Maybe this could be useful for some MIDI music experiments with minimal fuss: Excluding UARTs and FIFO (reused modules), the actual RTL code that does all the work is only about two screen lengths.

Here are a couple of links to the actual examples that he created, so make sure to click through and check them out for yourself.

  • Papilio Pro MIDI Monitor – (zip file)
  • meepMeep – (zip file) – This one is a MIDI monitor that actually makes an audible impression with an 18-bit saw waveform.  Offroad says it sounds like a Farfisa!  (See image above) Yikes indeed!

Do any of you guys have anything interesting that you’re working on for the RetroCade?  We’d love to hear about it!  Feel free to post to the forums, or comment on this post!  Right on.

(via the forums, and thanks to Offroad)


Firing Up The RetroCade Synth: First Impressions

Wednesday, July 3rd, 2013

We found another great article by Phillip Howard from Raspberry Pi @ Gadgetoid, this time on Getting Started With The Papilio RetroCade Synth. In the image above, you can see the RedroCade MegaWing plugged into its host Papilio Pro. This is the setup that Phillip used for the purposes of his article.

After some initial fussing with Windows 8 drivers and dealing with a reversed polarity situation from MIDI note on/off commands, Philip found himself having a genuinely great time with the synth. Let’s check out some of his findings from the article:

The beauty of the RetroCade is not that is incorporates an FPGA clone of the legendary Commodore 64 SID and Yamaha YN-2169 chip, but that both these hardware implementations, and the Arduino-like Sketch used to drive them are completely open and user-editable.

Playing with the RetroCade was a nice, Friday-friendly introduction to Papilio and once everything was up and running it was really a joy to play. The synthesizer is alarmingly powerful, and exudes nostalgia, but the software has both room for improvement and the opportunity for any user to delve in and make those improvements.

We really appreciate the kind words and your candor, Philip. I know that many people are excited to give the whole synthesizer hacking thing a go, and your article shows that it is really not as difficult as one might imagine it to be.

This is a great segue to a new blog series we will be sharing with you during the coming weeks in this space. We will be sharing a first-timer’s efforts in using the Papilio Pro, the Retrocade Synth, and the LogicStart! Should be interesting!

You can check out Phillip’s full article on his RetroCade experiences here.

(via Raspberry Pi @ Gadgetoid)

Sale! $20 Off Papilio Pro And RetroCade Synth Bundle!

Wednesday, January 30th, 2013

Great news!  We’ve finally got the Papilio Pro and the RetroCade Synth in stock here at the Gadget Factory store.  To celebrate, we’re going to make you a deal.

Starting today, and only for a very limited time, we’re offering TWENTY BUCKS off the Papilio Pro and the RetroCade Synth when purchased together. Call it a bundle!

This offer is only available at our own storefront, and is valid while supplies last.  These will sell out fast at this discounted price, so get yours now!

Keep in mind that we offer fast and affordable domestic shipping as well as low-cost international options.

Here’s a link to the bundle in the store for your shopping convenience.

Happy hacking.

Some Thoughts On Mixing Digital Audio

Sunday, January 20th, 2013

Mixing audio in the digital realm has some inherent limitations.  These limitations become more pronounced the less data there is to work with (i.e. low sample rates etc.). We found an article by software developer and author Viktor T. Toth that addresses some of these issues.

In real life, when you hear audio from two sources simultaneously, what you hear is the sum of the signals. Therein lies our problem. If you hear a group of ten people singing, the result will be louder than the singing of one person. A giant choir of a thousand will be even louder. A hundred thousand people singing an anthem in a sports stadium can be outright deafening. The point: there is no upper limit; the more voices you mix, the higher the amplitude.

With digital audio, we have a limited dynamic range. Let’s say we use 8-bit sampling; that means that every data point in the audio stream is a value between 0 and 255. When we add two such values, the result may be anywhere between 0 and 510, which simply doesn’t fit within the allowable range of 0-255.

Mr. Toth’s article goes in to detail about why using normalizing as a mixing method doesn’t hold water, and how using it on low sample-rate signals is an especially bad idea. The author busts out some math to dive into a couple of workarounds for mixing low resolution audio without normalizing, and he’s got some pretty good ideas here.

Great read – be sure to check out the full article at Viktor’s site.  If you’d like to chime in, feel free to do so in the comments.


Additive Synthesis Using Altera DE2-70 FPGA

Friday, December 14th, 2012

We found an interesting video on YouTube demonstrating additive synthesis on an FPGA – in this case an Altera DE2 board. These guys have set up a MIDI controller keyboard to send note-on, note-off, and velocity for each note played to the DE2. The DE2 has been programmed with VHDL to decode the MIDI messages, and generate a sine, square, triangle, or sawtooth waveform. This data is then run through their TEK TDS-210 oscilloscope for visual feedback, and of course to the speakers so we can hear the results.

Additive synthesis is based upon the “addition” of simple waveforms to create complex harmonics (overtones), which to the human ear result in a more interesting timbre, or tonal quality. Additive synthesis is one of the four basic types of sound synthesis, the others being subtractive synthesis, nonlinear synthesis, and physical modelling synthesis. An FPGA board (including the RetroCade!) can be programmed to achieve each of these types as well. There are many other types of synthesis also (granular, wavetable, etc.) but some of these would inherently be much harder to program. Not saying it can’t be done though!

These guys in the video wind up creating some great MiniMoog type sounds, and even manage to pick out that awful techno song that they play at hockey games… ha ha. A very cool project overall, and definitely something that can be done on our own RetroCade Synth.

To all you RetroCade users out there, we would love to see what you’re working on. I’m sure there are a lot of cool synth projects underway, so keep us posted on what you’re up to!

Happy hacking.

Some Cool Ideas For Hacking With The RetroCade

Tuesday, December 4th, 2012

Hola, amigos!

We found some cool videos on YouTube showing what other folks are doing with FPGA audio synthesis that we’d like to share with you. You may find some inspiration/ hacking ideas herein; these are just some of things that are possible with FPGA synths (such as our own RetroCade Synth)!

There are some interesting ideas on display in the videos – they might just light a fire in your brain and give you some ideas for how you can hack around with your shiny new RetroCade.

–Just like on our Kickstarter demo video for the RetroCade Synth, this guy has made his own touchscreen interface for his FPGA kit. You could really make any kind of touchscreen controls you want/ need for your project!–

–It is well within reach to implement effects processing like this on the RetroCade hardware. It’d be really cool to figure out how to vocode with the synth. Robot voice, anyone?–


I don’t know about you, but seeing stuff like this always gets my gears spinning. The possibilities are really only limited by your own creativity and drive. We can’t wait to see what you guys come up with on the RetroCade Synth, so make sure you shoot some video of your projects and send your footage our way. We’ll even post some of your crazy and cool videos here on the blog!

If you’d just like to share your ideas, feel free to post in the comments!

RetroCade Hardware Guide and User Guide Available Now; Final Hardware Launching Soon!

Tuesday, November 20th, 2012

In anticipation of our final RetroCade Synth hardware launching within the next couple of weeks, we wanted to take a minute and point everyone in the direction of the updated RetroCade Hardware Guide and the RetroCade User Guide:

These webpages are “works in progress” at this point, but are being updated constantly – so check back to these pages *often* for the very latest.  If you’re interested in FPGA audio synthesis at all and are unfamiliar with our RetroCade Synth, make sure you check out the Retrocade home page for a great overview of the product, some video of this little bad boy in action, and some general tech specs.

So get your knowledge on!  And get ready for some hackable chip-tune synthesis action with the RetroCade Synth by Gadget Factory.

Additional links:

Questions?  Ideas? Flattery?  Hit us up in the comments section, and stay tuned to the blog here for all your RetroCade developments.

1st RetroCade Synth Prototypes! RetroCade MegaWing, Arcade MegaWing 2.0, and Papilio Pro!

Friday, July 13th, 2012

The PCB’s for the RetroCade Synth prototypes arrived early this week which was way faster then expected. I put together a bill of materials (BOM) this week and put in a parts order to verify everything. The parts arrived last night and I built the first prototypes this morning!

Here is a video showing the first RetroCade Synth prototypes:

I will be testing everything next week and if all goes well I will be placing a larger parts order once the Kickstarter funds are released by Amazon. For everyone who backed at the prototyper level this means that I will hopefully be shipping your first boards out in just a couple weeks!