A recent development, secondary keyboards may be the easiest way for the greatest number of users to add hardware input, because the requirements are slight. Because I have my mouse on a ps2-to-serial convertor, I have a free ps2 port on my computer. I can attach a second computer keyboard to this port, and open it as a hardware input device in gdam. I can then use keys on the second keyboard to control gdam, without worrying about window focus, and while simultaneously using the normal keyboard for whatever I need. Perhaps better than a standard keyboard would be a bank of 10-key pads, one for each turntable... if i get a USB port, i'll look into it. The default input.devices file contains a line:
/dev/psaux none GdamPs2Keyboard |
which should allow any user with a second keyboard on /dev/psaux to make immediate use of it.