My portable music computer design
I made myself a portable PC for live shows. It's a portable desktop that has midi controls instead of a keyboard. Using a desktop CPU means it's faster than any laptop I could afford and didn't cost much to put together. The midi controller part uses 360 degree continuous potentiometers from Alpha which is a good way to make hi-res rotary encoders for cheap. All the files needed to 3d print your own, plus the PCB files and firmware for the midi controller part are here.