Cart64out is a breakout board for the Commodore C64 Expansion Port
 
All signals of the C64 expansion port are connected to a box pin header. This way, they can be displayed with a logic analyzer or an oscilloscope. A helpful feature for analysing the functionality for a cartridge. Some configuration and chip select signals are connected to a jumper, hence they can be interrupted by pulling a jumper, which might be useful for copying a cartridge. To provide a perfect timing for this, a micro controller could be connected to the Jumper JP1.
Also the signals from J2 can be connected to a bread board.