How Hardware Connects With Software on Early Consoles

The games on these early consoles we called cartridges and the cartridges were literally a hardware chip wrapped in plastic that you inserted into a receptor. And the hardware chip was ROM read only memory. Now there were some advanced NES games that also had a bit of RAM and some more advanced circuitry on the cartridges. But most of the memory, most of the circuitry was just a pure ROM chip read onlyMemory. So you insert this read only memory chip into the console and the console reads the game and the graphics data from that read onlymemory.