I am developing a custom cart and am re-thinking my approach to the CIC lockout chip. My initial design doesn't do anything about it (I test on a toploader), but I was planning on putting a socket on the board to hold an actualy CIC chip.
However, I recently purchased some unlicensed Tengen games (Pac Man and Ms. Pac Man) and I'm thinking about using a lockout defeat circuit like they do. The games work fine on my systems, and presumably they work well on all systems since they were sold commercially. I haven't double checked, but I'm assuming they use the -5V charge-pump circuit to trick the NES's CIC. I suppose they could use the Rabbit chip developed with the stolen code from the patent office, does anyone know?
So does anyone have any advice for how I should go? Here are the options I'm debating:
- Socket for a CIC chip. This is nice, but I'm guessing most people don't have the equipment/skills to remove a CIC chip without destroying it. Plus there are the region coded CIC's. Also, I hate the idea of ruining a 20 year old game cart. Maybe if I could find a supply of dead games, with functioning CIC's.
- Use one of the lockout defeat circuits. I heard that these were not completely reliable and/or safe, but I don't know where I heard that. Anyone know of the caveats with this approach.
- Put both the lockout defeat and the socket on the board, selectable via a jumper. Makes the board a little more complicated and large, but also versatile.
However, I recently purchased some unlicensed Tengen games (Pac Man and Ms. Pac Man) and I'm thinking about using a lockout defeat circuit like they do. The games work fine on my systems, and presumably they work well on all systems since they were sold commercially. I haven't double checked, but I'm assuming they use the -5V charge-pump circuit to trick the NES's CIC. I suppose they could use the Rabbit chip developed with the stolen code from the patent office, does anyone know?
So does anyone have any advice for how I should go? Here are the options I'm debating:
- Socket for a CIC chip. This is nice, but I'm guessing most people don't have the equipment/skills to remove a CIC chip without destroying it. Plus there are the region coded CIC's. Also, I hate the idea of ruining a 20 year old game cart. Maybe if I could find a supply of dead games, with functioning CIC's.
- Use one of the lockout defeat circuits. I heard that these were not completely reliable and/or safe, but I don't know where I heard that. Anyone know of the caveats with this approach.
- Put both the lockout defeat and the socket on the board, selectable via a jumper. Makes the board a little more complicated and large, but also versatile.