The VDrumLib COSM editor uses a spreadsheet form to allow you to see and edit ALL of the instruments for all of your pads at the same time.  One thing that is of special interest to TD-12 owners is that many of these parameters are not accessible from the TD-12's built-in editor.  These special TD-20 COSM parameters can be heard on your TD-12, but the only way you can see or change these "hidden" COSM parameters is with the VDrumLib COSM editor.  Here is a list of the COSM parameters that TD-12 owners can access only via VDrumLib: Five Mic Positions, Eight Levels Of Snare Buzz, Three Kick Beater Types, Hi-Hat Tambourine, and Cymbal Rivets and Chains.

COSM editing is accomplished via a drop-down list.  To access the drop down list for a given parameter, just click on any cell that has a triangular drop-down icon.  If you want to cancel the drop-down list without making a selection, then just click outside of the list.  However, if you do want to make a change, then move your mouse to scroll down the list to your choice and click on that choice.  The change will be made immediately on your computer, but it won't be sent to your module unless you click on the Send To ... button located at the upper right corner of the window.

The drop-down list at the upper left of the editor window allows you to change to another kit to copy or edit any of its instruments.  Another way to change kits is to use either the up or down arrow buttons located to the immediate right of the drop down list.

The editor window has the same Copy and Paste operations that are on the main Window.  You can access these functions by any of the following means (1) from the Edit menu, (2) Right clicking on a given instrument, or (3) via keyboard shortcuts.  The screen image below shows how to copy an instrument using the "right click" method to pop-up the Edit menu.

VDrumLib offers several types of paste operations that can be used to paste instrument data: (1) Paste both Head and Rim instruments (ctrl+V), (2) Paste only the Head (ctrl+H), (3) Paste only the Rim (ctrl+R).  There is also a function to exchange/swap the instruments between the head and rim (ctrl+W).

To move instruments to different pad locations, you can just drag each instrument to the desired pad.  Unlike the copy and paste operations, though, the MIDI parameters are also dragged with the instrument to the new pad position.

As you make changes to a kit, you might want to hear what it will sound like on your drum module.  To send a single kit to your drum module, you can press the Send To ... button located at the upper right corner of the editor window.  The "Send Data From:" label shows the kit number and name of the kit that will be sent to your module.

When you are done editing your kit, you can return to the main VDrumLib window and choose to either keep or discard your changes.  If you want to discard your changes and revert to the original kit, just press the Cancel button. However, If you are happy with your COSM tweaks, you can press the OK button to keep your tweaked kit and return to the main VDrumLib window.  Note, your changes will NOT be saved to disk at this stage.  They are just copied to the new kit library list in the main window.  If you want to save your changes to disk, you have to use the save button on the main window to save your new kit library.