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Just watched the Descent video.

Wow.

Good work.

This layout of steps was just off the top of my head, and I may have misled you somewhat. This was intended as an illustration of the opl2. With 2 operators per voice. I was referring to the fact that op1 modulates op4 and op2 modulates op5 etc. I have always wondered if this odd arrangement was to ...

I don't know if the Yamaha chips have a pipeline, in which the calculations actually take more than 8 cycles, but they overlap.

i.e. the first operator has been looked up, and envelope shaped and is now out of that part of the chip in time for the second operator to be envelope shaped, while the ...

The teensy is capable of switching the I/o pins once per clock cycle. Slew looks to be a problem, but I can achieve a passable clock at 10.6 MHz which is within tolerance for the OPL-3. I might be able to improve the slew rate.

The 'scope that I'm using is only just capable of measuring this stuff ...

Potential hardware speed issues aside, the actual programming of the teensy is lovely.

The 34 digital gpio pins that are exposed and spread across 5 32-bit banks. Setting up the direction and hardware properties of the pins can be done in just a handful of instructions for each bank.
And once the ...

I'm not sure how fast I can actually clock the GPIO on this device.

Certainly by avoiding the arduino libraries for GPIO I can toggle the GPIO registers once per clock cycle, which is pretty much 6 times faster than I would need to satisfy the clock of the OPL-3. But I haven't proven that the ...

It's a long time since I looked at this, but I went through the topic on Envelopes and I don't believe that your suspicion is correct.

http://forums.submarine.org.uk/phpBB/viewtopic.php?f=9&t=16&start=20#p1610

When you take into account the key rate scaling, the data tables for the OPL-4 show a ...

And this is my new hardware for opl-3

IMG_20141003_084000520.jpg

I've not yet put the opl on here, I'm just experimenting with the microcontroller.

This is a teensy 3.1 , which an arduino compatible microcontroller built around an ARM cortex m4.

The actual microcontroller device is a freescale ...

This is my newest board for the opl-2.

IMG_20140813_143244352.jpg

On the left is a socket for the pi cobbler.

Then there are two txb0108 auto sensing bi-directional logic level shifters. These are on ready made boards from adafruit and they're great for dealing with the voltage mismatch between ...

Current state of play.

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