Thought I'd share this here. After modding a NES console with a USB CopyNES, I've written a desktop-side MIDI driver that pushes live APU register changes (in real-time!) to the NES with zero latency. The connection speed is fast enough to stream LFO data streams (ie: vibrato, tremolo) and even DMC PCM samples in real-time without the need for storing them in NES CPU memory and triggering. Which opens up a ton of possibilities.
In a nutshell: I wrote a custom desktop MIDI driver that holds all 2A03 register state information and contains all the logic to translate MIDI notes, CCs, etc. to appropriate APU register changes ($4000 ... $4017). The only data being transmitted over USB (currently 460800 baud rate but higher rates may be stable) is the actual register bytes being received on an interrupt in real-time, so it's essentially zero-latency and very responsive. (It's utilizing a USB CopyNES installed in the system as a way to write to the APU registers.)
The goal is to make all features of the 2A03 chip available as MIDI CCs so you can emulate the behavior of trackers in a MIDI-compatible DAW (Logic, Cubase, Pro Tools, Reaper, Ableton Live, etc.) and to aim it towards power-users (surpass the basic feature set of the midiNES / Chip Maestro) and thereby make it available for sequencing in parallel with other synths/samplers and audio in your DAW and not be restricted to working within a tracker.
Current features of note:
- implemented software-driven modulation (vibrato, tremolo, etc. - any APU parameter can be modulated with depth & rate)
- implemented software-driven sequence macros (akin to Plogue Chipsounds' Wave Sequencer) so note triggers can execute complex sets of user-programmed APU events during the attack, hold (loop), and release period of notes. These presets can either be stored in your DAW session as MIDI SysEx data so they are portable and platform-agnostic, or stored in a global settings file that the driver can load from disk when you open your DAW session
In future versions it might be possible to:
- stream NSF files direct from the desktop in real-time without requiring a RAM cart or side-loading/buffering
- have potential to receive real-time direct APU output stream from Famitracker or a modded NES emulator
Here's some preliminary videos demonstrating that it works. I'll get a full video put together eventually when all the features are implemented.
https://twitter.com/orchetect/status/1044542051755319296
https://www.instagram.com/p/BpEBwqAADaK
In a nutshell: I wrote a custom desktop MIDI driver that holds all 2A03 register state information and contains all the logic to translate MIDI notes, CCs, etc. to appropriate APU register changes ($4000 ... $4017). The only data being transmitted over USB (currently 460800 baud rate but higher rates may be stable) is the actual register bytes being received on an interrupt in real-time, so it's essentially zero-latency and very responsive. (It's utilizing a USB CopyNES installed in the system as a way to write to the APU registers.)
The goal is to make all features of the 2A03 chip available as MIDI CCs so you can emulate the behavior of trackers in a MIDI-compatible DAW (Logic, Cubase, Pro Tools, Reaper, Ableton Live, etc.) and to aim it towards power-users (surpass the basic feature set of the midiNES / Chip Maestro) and thereby make it available for sequencing in parallel with other synths/samplers and audio in your DAW and not be restricted to working within a tracker.
Current features of note:
- implemented software-driven modulation (vibrato, tremolo, etc. - any APU parameter can be modulated with depth & rate)
- implemented software-driven sequence macros (akin to Plogue Chipsounds' Wave Sequencer) so note triggers can execute complex sets of user-programmed APU events during the attack, hold (loop), and release period of notes. These presets can either be stored in your DAW session as MIDI SysEx data so they are portable and platform-agnostic, or stored in a global settings file that the driver can load from disk when you open your DAW session
In future versions it might be possible to:
- stream NSF files direct from the desktop in real-time without requiring a RAM cart or side-loading/buffering
- have potential to receive real-time direct APU output stream from Famitracker or a modded NES emulator
Here's some preliminary videos demonstrating that it works. I'll get a full video put together eventually when all the features are implemented.
https://twitter.com/orchetect/status/1044542051755319296
https://www.instagram.com/p/BpEBwqAADaK