Multi Region N64

Inside my multi region n64. Automatically detects cart region when inserted

 

I replied on the other thread you answered to, but for the sake of everyone here, this is a bulk copy and paste
Now that is high-resolution gold! It's also pretty self-explanatory as to what's going on, but I find it odd that there are four analogue switches there when three would suffice. I'd love to see the underside of the board (if possible) as it'd allow us to start piecing together where the traces go.

What I also found unusual with that mod is that pin 25 has been cut and joined to the EEPROM dat. The mod I was working on survived fine until I started messing with that wire in particular. Long story short: I did succeed in making a simple PCB for a multi-region unit and even started working on a V2 of the design, but the the unit that was was experimenting with has died and I'm out of money to pursue this project any further.

Too add to this pool of knowledge, I got an email from a friend pertaining to what that microprocessor in the middle there could be doing:
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Right at boot, either the first or second thing the PIF does is send a signal for the region it is. If the CIC doesn't respond with the corresponding signal it should lock before anything else happens (for instance, before IPL2 is loaded to PIFRAM) Pretty sure NTSC is 110 and PAL is 100, but that info is second-hand. An MPAL PIF has never been examined as far as I know, but since they're compatible with NTSC carts fairly safe to say they report the same.

IPL2 sets S4 to the region used by software, independent of the initial check. That's how bootloaders are able to change the detected region around. That doesn't guarantee the software is going to appreciate you doing that, of course.

Also, the main CIC<->PIF runtime algo alters nibbles in reverse order. Pretty sure the 7xxx series does high nibble to low nibble, and the other series all do low to high. Might want to double-check that too, but should be the case. The results have to match between the two or the system will lock.

Ideally, you'd just want to program a new PIF that avoids region checks altogether. It's an SM5-based chip--just like the CICs are--and there's an assembler online. Seems like an awful lot of work though for something that can be solved easier software-side.

 

Thank you for your hard work. I was wondering if we can provide any help (financial or technical) to get an open source solution for a switchless n64 ?
You talked about a german forum earlier but did someone get an otaku-store's n64 in their hands to understand how exactly it works?

 

I don't think that's necessary - it's pretty obvious how it works. They have both PIFs on the board, and switch between them with a bunch of analog multiplexers. When you plug a cart in, it tries one of the PIF chips and sees if it can handshake with the CIC inside the cartridge - if not, it switches to the other one. The main problem with this approach is that you need both a PAL and and NTSC PIF for it, and the only place you can get them is from an N64, which immediately raises the question of why you just don't use both consoles.

 

True, but there's usually a fairly sizeable price difference between a loose N64 and a complete one. There's also the element of doing it just because, otherwise we'd all just be playing emulators on our PCs, like every other Youtube comment suggests on a retro hardware video.

 

I certainly wasn't decrying the idea of using real hardware. I just think it would be a lot better to do this by simulating the PIF rather than killing a N64 to get one of the correct region.

 

Is there a way to clone a PIF or make one that integrate the PAL and NTSC one on a single chip ? I'm not an expert at all but the "open source solution" i was talking about earlier was more something in this direction.

 

My understanding is that the PIF has been decapped but that it would be a ton of work to reimplement for not that great of a reward for the most part. Would love to see an 'UltraPIF' though at some point.