BPMC DIY Series: Modifying the Turbografx 16

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Welcome to the second installment of the BPMC Do-It-Yourself Series. Think of these posts as starting points rather than definitive mod guides. I only took these projects as far as I saw fit for my own purposes. It is up to you to pick up where I left off and make these machines your own. Some of what I’d like to explore with this series is the more off the beaten path stuff. In the first post we highlighted the damned-near-extinct JVC JX titler and while I think it is helpful to see how people approach modifying machines I would like to actually see people getting their hands dirty on this shit.

Which brings us to today’s machine, the not-altogether-impossible-to-find NEC Turbografx 16. I’m not sure I would say it is my favorite 16 bit piece of hardware considering what developers got up to with the Genesis in it’s final years but it is a really unique machine. It has an awesome lineup of games, a number of cool peripherals/accessories (cd-rom ooo la-la) & a spicy sleek physique. While a little price-y compared to it’s peers deals can still be found especially if you don’t mind a little cosmetic damage. This was a mod of mine from the early twenty-tens and I did up a small batch of three. Kept one for myself and am dusting it off for the occasion.

If you’ve prodded around a Genesis or a SNES you know what to expect here. The TGFX16 shreds like any other 16-bit system and serves up a colorful glitch salad of block-y crunch-y color chunkies. The video starts off with some mangled clock timings in Legendary Axe, followed by a broken-beyond-repair round of Space Harrier. Sticking with Space Harrier I run through a number of the audio driven effects utilizing the music from the title screen. From there I’ve included a bunch of corrupted gameplay worth highlighting.

Inside the TGFX16 lies an 8-bit CPU and a dual 16-bit GPU. There are many points of entry to launch your righteous crocodile clip bite on this thing however I chose to focus on the Hudson Soft HuC6270 VDC as it houses a satisfying number of bends. Feeding the upper GPU points into one another creates a rich library of stack-able corruptions. They also respond well to being hit individually with an incoming audio signal. If you are looking to play it safe this should provide you with all the corrupt graphical entertainment you need. If you are interested in probing further cautiously take a look around the 270’s side pins for more graphical corruptions, clock-speed control (one of my favorite features) & minor audio corruption (although peep the 280A Hud chip for sound generation). Bending with a 70 ohm resistor or something in that neighborhood is a good look on the buffer tip. Before you dig in on your 270, MAP OUT THE GROUND! The ground lurks. It lurks! Follow the traces and make sure none of them connect up to any questionable large green spaces.

Modifying the T16 requires a steady hand and fine wire as you’ll be wiring directly to the chippy to create your corruptions. If you are comfortable working on wiring up a Genesis then you should be in good shape. Make sure to use a fine soldering tip and forgo using regular ol’ hookup wire. If at a loss for tracking down some high-gauge wire just tear apart some SCSI or serial cables as that is what I usually do. Make sure you give yourself enough length to reach the booster. If you are afraid of hitting the 270 with too much heat you can trace back the points to the other chips or to the tiny thru-hole terminals and wire them up from there. If this is the case however you will need to track down some really fine wire, in the 30-36 AWG range, to fit them’ holes. Make sure to hit those little jammies with some Flux paste. It can be a challenge to get them to stick.

I did a couple of goofy things for my mod. I permanently affixed the Turbo Booster to the TGFX16 that way I could wire out my GPU points to the empty spaces in the Booster. Otherwise if you were to try to house your mods directly in the TGFX16’s housing you’ve only got a sliver of space to utilize. On the TGFX16 itself there is enough room on the side for some switches however pots might be a stretch. Having to utilize the Turbobooster is a blessing in disguise. While they are expensive they really clean up your output audio & video. The RF out is puppy puke in comparison. Edge feedback or sync corruption anyone?? With the booster’s guts exposed implementing video amp mods of any sorts are right there waiting for ya. I’ve wired my points out to a little patchbay and then added a set of patchable knobs of varying resistance values on the other side. You’ll notice there is a 1/4 jack for audio visualizations. The white jacks are a little breakout section for the audio signal so that you can either patch the audio directly into the glitch jacks or into the knobs to vary audio feed amounts.

Brief, I know, but there it is.. enough to get started.  I hope you enjoyed the second edition of the BPMC DIY series.  What’s next?  Interested in turning a DVD player into an audio/video synthesizer? Or how about my Atari Video Music mod?  Have a piece of gear in mind?  Let me know via the contact link below.  I hope you enjoyed.  Until then….

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