The SOL-20 keyboard doesn't have space for mounting holes right next to the matrix header, so the new footprint eliminates those mounting holes.
- Add extra key to the left side of row 4 to permit "inverted T" for those who want it. - Tiny shifts of several keys to correct key distances - Include mounting holes with daughter board connector, to ensure consistency.
Add library modules for OSI mounting holes on PCB, and holes in the aligner for spacers to pass through.