MSX Do It Yourself Enhancements
See also the Books and Magazines pages for do it yourself items. And the Technical information for computer-specific information.
Choose from the menu one of the the DIY article groups:
You want to design a MSX cartrdige? Make a PCB with Cadsoft Eagle freeware edition.
Download the Eagle MSX cartridge library by Arnold Metselaar, that may help you design a cartridge PCB with the MSX connector.