OpenC64TapePortBreakOut is an Open Hardware PCB that breaks out all the pins on a Commodore 1530 Datassette Connector. It is mainly useful for building Tapuino devices.

A prototyping cartridge with cart connectors and/or header pinsWith this you can add cartridge edge connectors and/or header pins, quite useful for doing diagnostics or other kinds of fun with the Commodore 64/128 cartridge port.Component list, recommended but not requiredDIL/SIL headers 2.54mm pitch44pin Edge connector 2.54mm pitch, vertical and/or horizontal
 
Another Prototyping cartridge - or developer board
This is used for generic prototyping for which you can make connections soldering wires to the desired pins.