This is a version of the files from https://gigatron.io/ altered to work on a vanilla KiCAD 5.1.6. Changes are minimal in the schematic and PCB, layout has only been changed where dimensions or orientations changed as a result of symbol change.
The PCB has been routed with FreeRouter automatically. https://freerouting.org/
The Omega symbol has been removed as it broke the routing software.
No Copyright is claimed and rmeinas was the original creators of Gigatron.