First post, by RJDog
So, inspired by the HardMPU project undertaken by ab0tj, as well as the likes of Dreamblaster and especially the recent discussions around the use of a Raspberry Pi 3 as a MUNT host, I have decided to develop and produce (at least some prototypes) an MT-32 WaveBlaster Card.
No, the plan is not to simply attach a Raspberry Pi 3 to the WaveBlaster header... my plan is slightly more involved, but I will admit the thought crossed my mind. I am currently debating between a Broadcom BCM2835 (aka. Raspberry Pi Zero) and Allwinner H2+ (aka. Orange Pi Zero) as the core CPU/SoC. Definitely a Atmega 328 or similar as a MIDI interface, although I will probably try wiring the MIDI signal directly to the SoC, just to see how that works out. Based on my readings, I can expect about 500mA to be available to the card from the WaveBlaster header, which is nothing to shake a stick at, but can be a limiting factor, hence the choice in processor. The Broadcom sips a mere 50-100mA (depending on configuration) where the Allwinner consumes 200-400mA (again, depending on configuration), but the Allwinner has a much better audio output than the Broadcom. The Allwinner also is a quad core... Broadcom a single core, but otherwise nearly identical ARM processor. MUNT is not a particularly multi-threaded process, so I'm not sure if that's much of a deciding factor.
I thought about making a standalone MIDI unit... essentially a modern made MT-32 (albeit somewhat emulated)... but after thinking about it I think the WaveBlaster card is both more challenging (a good thing, in my books) and more versatile. One could simply use a unit like Dreamblaster's WaveBlaster Module MIDI Interface Board to turn it into a standalone unit and, when used as a WaveBlaster board attached to a compatible sound card, it all fits neatly inside your computer case.
I think the really ambitious part of this project is how I'm hoping to allow the user to interact with the card. I could go the same route as the Dreamblaster X2 and provide a USB interface to manipulate files and configuration (which, by the way, very clever, props to Dreamblaster), but I believe I can get it to work via special MIDI SysEx messages from the host system itself (a special interface program would be required on both the host system and card, of course).
One of the main things that would need to be able to be accomplished through the host-card interface is the ability to upload ROM files to it. I'm not 100% sure, but I think there would be some questionable legal issues distributing Roland ROM files with the card.
Anyway, that's my retro-oriented activity that I think is going to occupy me for the next couple of months. Look forward to your thoughts and suggestions.