C64 Userport Expander is a remake of a project from a "64'er Sonderheft" magazine.
You can find the scan (german language) here.
The driver software can be found here.
The C64 Userport Expander expands the C64 Userport from 8 Bit to 3x8bit.
The whole KiCad project is provided inside subfolder "kicad".
Please feel free to order your own PCBs, Gerber files are here "gerber".
I would be pleased about a small donation: PAYPAL.ME