Getting Up and Going with the Control Surface Integration Project.

What is CSI?

CSI is a project which was started a couple of years ago in order to make the integration of control surfaces into Reaper much more powerful. Before discovering CSI, David used to use Klinke’s MCU driver, which did the job, but doesn't seem to be under active development at the time of writing.

In this article, we'll be covering the requisite steps to configure CSI for a Mackie Control Universal (MCU) compatible surface.

This article is by no means conclusive, but should you wish to take a deeper dive, there are plenty of other resources on the Reaper.fm forum

Preparation.

There are a couple of things you should do in Reaper before getting CSI installed:

1. In the MIDI Devices category of Reaper's preferences, make sure that both the input and output ports for your surface are completely disabled.
2. While you're there, make a note of both port IDs. You’ll need those later.
3. In the OSARA Configuration dialog (accessed by hitting Control+F12 on Windows or Command+F12 on Mac), find the "report changes made by control surfaces" check box, and make sure it's checked. If you don't have that check box in your OSARA Config dialog yet, update your copy of OSARA to the most recent snapshot.

Installing CSI.

At the time of writing, you can get version 1.0 of CSI from the Reaper Stash

CSI will arrive in your downloads folder as a zip archive, and when you open it, you’ll find the following:

1. The CSI folder. On Windows, copy this folder into %appdata%\REAPER in its entirety. On Mac, the correct path would be /Library/Application Support/REAPER.
2. Several DLL files. Choose the relevant file for your surface, and copy to %appdata%\REAPER\UserPlugins on Windows, or /Library/Application Support/REAPER/UserPlugins on Mac.

Having placed those files, you’ll need to go back into Reaper and do the following:

1. Open Preferences.
2. In the category tree, go to Control/OSC/Web.
3. Hit the Add button.
4. You’ll be presented with a list of surfaces that Reaper can support. Choose Control Surface Integrator.
5. Hit the OK button.

Editing the CSI ini File.

Editing the CSI.ini file is how you'll configure CSI for your specific surface and system. It can be found in the CSI folder you copied above.

You can edit it in notepad or any clean text editor, but we'd strongly advise you to digest the explanations below and tread carefully while editing.

Ready? Nerd alert in 3, 2, 1...

On the topmost line of the CSI.ini file, you’ll find the word "Page" followed by a lot of information. De-jargoning this line is beyond the scope of this article. Suffice to say, don’t delete or modify this line under any circumstances until you know what you're doing, or the bottom will most assuredly drop out of your world (and potentially your britches, too).

Let’s assume that you have a Mackie Control Universal compatible surface.

Arrow down through the CSI.ini file until you come across a line which reads:
MidiSurface "MCU" 13 15 "MCU.mst" "MCU" 8 8 8 0

This line is comprised of several key elements, let's examine them one by one in chronological order.

• "MidiSurface" specifies that it’s a MIDI surface.
• "MCU" specifies that this particular MIDI surface is called MCU.
• The first number (13 in the above example) specifies the input port ID for the surface. The second number (15 in the example above) specifies the output port. You’ll almost certainly need to change these as they're unique for each system configuration. If you remembered to note down the port IDs as suggested earlier, go ahead and change whatever's there to reflect your input and output port IDs. If you forgot, give yourself a gentle facepalm, go find them now (and believe us next time around).
• "MCU.mst" specifies that the controls which are defined for this surface are contained in a file called MCU.mst.
• "MCU" specifies that the zones for this surface are contained in a subfolder within the zones folder called MCU.

Next, you'll find a ream of numbers, each separated by a single space. Here's what they denote, again in chronological order.

• The first number (8 in the above example) specifies the number of channels the surface has. If you need to modify this in order to reflect the amount of channel strips your particular surface has, don’t include the master strip when you're counting your faders.
• The next number (again an 8 in the example above) specifies the number of sends the surface has available.
• The penultimate number (yet another 8 in the example that's now so far back in the document you'd be forgiven for forgetting you'd ever read it) specifies the number of FX menu options.

Lastly, you'll find a solitary "0", which isn’t currently used for anything. Don’t change or remove it, though.

Having explained all that, for most MCU compatible surfaces, the only things you'll likely need to change are the input and output port IDs (but hey, wasn't it fun learning about it?)

What Next?

If you've followed along with all of the above step by step, then when you next fire up a project in Reaper, your surface should spring into life, and OSARA will provide some speech feedback as you tweak and twiddle.

We've really only scratched the surface here. CSI is immensely powerful and configurable to boot. If you're thirsty to read more, please visit the CSI wiki on GitHub

What to Do if the Bottom Has Dropped Out of Your World (or britches).

We hope this all makes sense. If it doesn’t and you have problems or further questions, feel free to get in touch.

David fields questions related to CSI expertly on the RWP list.

Scott will be attempting to field questions related to CSI configuration (in other words, passing them along to David then unscrupulously hogging his credit) on the Reaper Access WhatsApp channel.