I recently lucked onto a NTSC copy of Panda's Tank Brigade. Unfortunately, when I tried inserting it into my 2600 Jr, the tightness of the connector ended up breaking one of the cartridge's internal supports.
The game is made very cheaply, but I thought it was interesting to examine how it was made. The shell is three pieces, a top, a bottom, and an insert for the positioning slots. That insert just slides in to the bottom half. The PC board is held in place by just three plastic supports. There's a single pin at the top of the board, then either side of the cart connector is held into place by small pins sticking up from the bottom piece. However, these don't go through a hole in the PC board but instead on the board's side. One of these is what broken in my cartridge. There are no screws in the cart design, it all just pops together, but it also means that the design is pretty weak, with small pieces of cheap plastic taking a lot of stress.
The PC board itself has TI (Texas Instruments) markings. On the back, it identified itself as
TMS4732-45 MGL B8405L ZA 35465 101 PANDA KOREA
The TMS4732 is a 4K masked ROM part. On this board, the die is bound directly to the PC board and covered in epoxy. The only other part is a capacitor that likely ties between power and ground to provide some buffering for the power supply. Looking at TI's data sheet, the masked ROM can be set to have chip select as high or low at programming time, so it doesn't need an inverter to flip that logic. Given that the TI logo is on the PC board, I expect that the whole thing was fabbed at TI, not just the die. I find it interesting that this little pirate shop used TI for their manufacturing; anyone seen any other TI-marked boards in their carts? Back in the 90's, I'd heard from friends at Motorola that 2600 ROM carts were pretty popular at their semiconductor fabs, so I guess Motorola was also doing some mask ROM production then.
