Gaming

19960 readers

1 users here now

Sub for any gaming related content!

Rules:

1: No spam or advertising. This basically means no linking to your own content on blogs, YouTube, Twitch, etc.
2: No bigotry or gatekeeping. This should be obvious, but neither of those things will be tolerated. This goes for linked content too; if the site has some heavy "anti-woke" energy, you probably shouldn't be posting it here.
3: No untagged game spoilers. If the game was recently released or not released at all yet, use the Spoiler tag (the little ⚠️ button) in the body text, and avoid typing spoilers in the title. It should also be avoided to openly talk about major story spoilers, even in old games.

founded 5 years ago

MODERATORS

Metallinatus@lemmy.ml

peternile@lemmy.ml

How do modern NES games get around the CIC chip? (lemmy.ml)

submitted 2 years ago by atocci@lemmy.ml to c/gaming@lemmy.ml

3 comments fedilink hide all child comments

I had the chance to pick up a copy of 8 Bit Music Power Final recently, a NES game released in 2021! Before this, I hadn't even realized games were still being developed for the NES, let alone receiving commercial releases.

I'm sure Nintendo has nothing to do with this continued support though, so it got me wondering about the CIC lockout chip. Supposedly, it should be in every officially licensed cartridge for the NES, and without it the console will refuse to start and repeatedly reset. Without Nintendo licensing games anymore though, how are these new releases managing to get around this?

I know there were unlicensed cartridges that used a brute-force method to bypass the chip back then, but these new games don't seem to be doing the same thing as those. Was the lockout chip reverse engineered at some point and that's how it's done now? I can't find too much information on this, but I'd really like to know how it works.

you are viewing a single comment's thread
view the rest of the comments

[–] Garrathian@beehaw.org 13 points 2 years ago (1 children)

https://www.youtube.com/watch?v=x8PYE8A-WEw

This guy has a pretty good video that discusses it. The short answer is that Atari in the 80s had filed a case in court and got the NES CIC chip code, and made an equivalent Rabbit CIC chip for their bootleg games (he goes more in detail about all of that). Later on the homebrew community struggled to reverse engineer the NES CIC chip or get it to dump it's CPU instructions. However they found out Atari's Rabbit one would dump the CPU instructions that were equivalent to the ones NES CIC used. So they used those instructions to reverse engineer the chip, which allowed homebrew games to be developed for the NES with the reverse engineered homebrew chip

[–] atocci@lemmy.ml 3 points 2 years ago

Wow thank you, that's super interesting and exactly what I was looking for! Amazing that it took more than 20 years for it to be figured out.