You'll need a virtual midi device so you can send midi from like Ableton/Reaper or whatever to Vice.
I use LoopMIDI under windows its free, tobias-erichsen.de/software/lo...e/loopmidi.html
(you'll need to download and config it first and make a midi port)
Start up your midi program windows mac or whatever to control the thing.
Start up vice, change the settings like above
Load up the d64
I haven't messed around with it much but you should be able to set sid params and stuff.
Also vice has tons of midi io devices you can emulate so I will be looking into other stuff.
So I am piping midi from Ableton live into it via a virtual midi device.