[Note: this post was originally a comment I appended to the post ‘Alternative Keyboards 4‘, which was about my double QWERTY keyboard instrument. In that place it was hard to find, and the illustrations disappeared when I changed my website, so I’m trashing the comment and transferring the text and images here].
In order to play the ‘blue’ keyboard (the left-hand one) properly, the Shift key needs to be pressed down so that it outputs different ASCII codes to the ‘red’ (right-hand) keyboard. Using ‘Caps Lock’ doesn’t work, as this only affects the letter keys, not the numbers or other characters.
It would be awkward to have to press the Shift key at the same time as pressing a note key every time, so this keyboard needed something to keep the Shift key pressed while playing. I didn’t want to do anything permanent to the keyboard, like gluing the key down, so I looked for a suitable clip, which could be slid on and off when needed.
There are two types of clips that do this job: a drawing board clip, used by artists and architects; and a table cloth clip, as used in the home. They all look something like this:
For a drawing board or table, the flat side would be on top and the bent side, which acts a spring, putting pressure on the end and holding it tight, would be out of the way underneath. For my application, I needed to use it the opposite way round, with the flat side underneath, so the keyboard could still stand on the desktop in the usual way.
I liked the look of the drawing board clip best, but in the end I found some table cloth clips in the sale in a local home shop, and bough those. They looked like this:
In this way, the ‘blue’ keyboard outputs different ASCII numbers from the ‘red’ keyboard, and can be interpreted separately by the program Pure Data which I use with the ‘double-keyboard’ arrangement.