As seen elsewhere on Denial, Retro Innovations has released the VIC-MIDI cartridge for the VIC-20!
I've been working on some code to implement the MIDI side of it. The MIDI In capability works very well (IMHO) but there are a couple of areas where I need some help:
1. MIDI Out capability. I added a very simple single-note output interface for testing the hardware, but what would be needed would be a table to track multiple keypresses and multiple notes, for Note On/Note Off. This would allow the VIC to be played like a keyboard, maybe with the Incredible Music Keyboard overlay.
2. I was never able to get viznut's waveforms to work reliably. They have to be applied at each note and I couldn't get the timing right.
3. The GUI is pretty plain, though I incorporated a font for it someone made a while back.
Here's the code and some preliminary documentation. Feel free to fork it! Alternately, I can give you access to the repo (PM me if you want to do this).
https://github.com/LeifBloomquist/VICMIDI
Help with VIC-MIDI Software
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Re: Help with VIC-MIDI Software
You have to switch the channels you want to viznut off for a couple of cycles until the shift registers get reset before. Cannot see it happening in that mess of illegal opcodes.Schema wrote: 2. I was never able to get viznut's waveforms to work reliably. They have to be applied at each note and I couldn't get the timing right.
Code: Select all
lda #$7e ; Turn off but set to highest frequency, so it's getting done as fast as it could.
sta $900a
sta $900b
sta $900c
sta $900d
ldy #0
l: dey
bne -l
; ...now viznut them
A man without talent or ambition is most easily pleased. Others set his path and he is content.
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https://github.com/SvenMichaelKlose