[fair_enough]

I reckon these official converters were instrumental in Tengen's work for reverse engineering the NES to run "unlicensed" games.

It turns out that another blog post on this site explains exactly that:

https://nicole.express/2022/the-center-point-can-not-hold.ht...

"How did they do it? As it turns out, crime. Unable to reverse engineer the chip, Tengen convinced the United States Copyright Office to hand over the source code of the lockout chip, claiming it was necessary for a lawsuit. With the code in hand, Tengen could make their own clone with ease. And Tengen was going to sue Nintendo for antitrust violations, so they probably figured they could get away with it."

This has got to be the most Cobra Kai thing a company has ever done to another company for the benefit of consumers, and I love every bit of it.

[wk_end]

The lockout chip isn't related to the converters, per se. The converter has a lockout chip, but so does every official NES game.

The Famicom didn't have any kind of protection scheme, so unlicensed and bootleg games were commonplace; Nintendo added the lockout mechanism for the international release precisely in response to that. Each cartridge contains a "key" chip that unlocks the "lock" chip on the NES main board, which then releases the reset line on the CPU allowing it to operate.

Naturally, this means that Famicom carts don't have the lockout mechanism, so those signals need to come from the converter.

[ndiddy]

> The Famicom didn't have any kind of protection scheme, so unlicensed and bootleg games were commonplace

Unlicensed/bootleg Famicom games weren't very common in Japan due to the control Nintendo had over game distribution. In Japan, Nintendo sold all their Famicom consoles and games through a wholesaler organization called Shoshinkai. If you wanted to sell Famicom games without a license from Nintendo, you needed to deal directly with stores and/or wholesalers who both wanted to sell Famicom games and didn't sell any Nintendo products. This limited unlicensed games to being niche underground products that were mainly sold in back-alley shops and through mail order. In the US, this level of control over distribution would probably be ruled anticompetitive, so the lockout chip was a technical solution that accomplished a similar goal.

[toast0]

FWIW, the chip on the game and the chip on the system are the same (within a region). Pin 4 is used to determine if it should be a lock or a key.

[platevoltage]

Which means disconnecting pin 4 of the lockout chip in the NES causes it to think it's a key and not reset the system, effectively disabling it.

[platevoltage]

There was also another method of bypassing the lockout chip that some of those awful bible games used. It was to put a capacitor in the cartridge to literally shock the lockout chip, disabling it long enough for the game to boot.