First, a bit of a history lesson is in order. The Roland CM-64 was one of several machines that were designed as a sequel to the MT-32 machine to provide early computers including Amigas, Ataris and DOS that only had a bleepy speaker system (more commonly used for error messages) with a fully featured external soundcard that could be used by a computer to sequence music AND sound effects in real time. The CM-64 combines an MT-32 with some other functionality from other Roland projects into one box and eschews further control, letting your software do all the talking to the unit.
A cut down version of the Roland U110 and Roland D110, which uses LA synthesis based on sample partials to create sounds of different timbres and hardness, as well as PCM samples and ROM-card technology to add additional sounds to its gamut from the U110 side. Sounds can be played together and sequenced on different MIDI channels, with channel 10 providing GM drum and sound effect samples and channels 11 to 16 addressing split keyboard effects and ROM card samples. It even has its own reverb unit on some of the programmes, making this a pretty complicated unit despite the lack of any kind of hardware control - just a power button and a volume knob on the front!
As there are not a lot of direct editing options, you will need to sequence it with older computer hardware, use it as an external synth module via a DAW in case you need a certain kind of sound, or you can just sample it and then use those for another project. The only caveat is that you need full MIDI implementation to get this working properly.
Working with Bitwig
This then throws up a particular conundrum with hardware and Bitwig, as I hadn't had much success with the standard containers you get in the programme. So I thought I would try and highlight how you can sequence the CM-64 and pretty much any MIDI device that uses programme changes in Bitwig (I'm using 1.1.11 at the moment, not sure if 1.2 carries a better implementation of MIDI).
First, get your MIDI Out of your interface connected to the MIDI In of your CM-64. The Left Audio Out of the CM-64 will allow you to output Mono only, so you only need one input on your audio interface for now.
Then it's a simple case of hooking up the right I/O in Bitwig. As Bitwig only handles MIDI channel data in the Hardware Instrument container, you need a more complete MIDI programme to address the individual programmes on each of the channels. The quickest and easiest answer I have found is PizMidi, a free set of MIDI VSTs that do all sorts of MIDI utility functions are easy enough to implement in a DAW. Annoyingly I found loads of references to this software but no instructions on how to set this up, so I hope this helps someone.
In Bitwig, make an instrument layer and set up your device chain as follows:
Make sure that the MIDI channel on the PizMidi PGCGUI matches the same one on the Hardware Instrument Container and you should be able to select the individual programme of each channel via the VST plugin. Even easier, you can map a slider or knob on your controller to change the programme quickly, but if you want to change the channel you will have to manually change this on the Hardware Instrument container to match. The PizMIDI VST module also adds crucial functionality for pitch bend (+/-12 notes) and 0-127 modulation to MIDI out messages that is currently missing in Bitwig's implementation of MIDI. It's strange that Bitwig haven't added this into the DAW already and marks a lacking feature in an otherwise excellent bit of software.
Anyway, I plan on keeping an eye open for new U110 ROM cards to use with it, as the strings and electric pianos are great for pads, the vocal "Ah" samples are lush, the sound effects are pretty wacky and some of the velocity sensitive slap basses and guitars are fun to use in a cheesy kind of way. Plus, the ROM cards have lots of authentic 909 and 808 samples on them as well. I'm glad that I have several already:
SN-U110-04 - Electric Grand & Clavi
SN-U110-08 - Orchestral Strings
SN-U110-07 - Electric Guitar
SN-U110-08 - Synthesizer
SN-U110-10 - Rock Drums
If you're looking to pick up a retro sound device, I wouldn't recommend the CM-64 unless you specifically need it for compatibility with older PC games. Purely for use as a sound production module, the Roland U110 and U220 offer all the same functionality and sounds in a rack unit version, which are probably a bit more user friendly and easier to store in a studio to boot. Both can be had for under £75 while the cards are between £10 and £25 a pop.