WTB: Tristar Adapter and WildCard DX2, Snes

It's the same as a "50/60Hz" switch except you use a register output instead of the switch.

 

Yeah, basically it works the same as a 50/60hz switch, just with the switch being substituted by a register that's acessible in software.
However, there's a bit more to it.

Many games check which video mode the Snes is running in in an attempt to prevent them from running on the wrong system by checking an internal register of the Snes.
Ultra16 reads out the region code of the inserted cartridge and overwrites the ntsc/pal flag of the Snes every time the above-mentioned register is checked with the value the game wants to see.
That way, Ultra16 can play games of any region in any video mode while automatically disabling any region protection.

 

By overwrite you mean substitute with a local register? Also do you intercept the flag's data bit or can the CPLD beat the PPU for contention?

 

I mean that every time the above-mentioned snes register($213f) is read, the cpld outputs its own ntsc/pal flag, beating the ppu in a state of bus contention, yeah.
I know this is usually strongly advised against, but i've tested this on a snes running for over 2 weeks straight and it worked without fail in both cases.(pulling the bus high and low, respectively)
Should be ok according to the cpld datasheet, too.

 

That's pretty interesting, I've never tried to do that but I can think of places where it'd be handy. Can you beat ROMs, TTL and NMOS logic too?

 

Haven't tried yet. Would come in handy to alter reset and irq vectors of roms on the fly for sure.
I guess results would be varying at best, though.

Ultra16 detects if there are other devices trying to do the same thing and shuts off its own deprotection feature in that case.(some import adapters and cheat cartridges do it aswell, that's where i learned this "trick".)

3 devices fighting for bus control can't be healthy, that's for sure.
It might just work out ok, but I rather like to play it safe than sorry.

 

Wow amazing mod, sorry to be a bit offtopic, I find this BS-X modem emulation very interesting!

But does this feature allow playing broadcasted games like Zelda 1 remake Map1/2 and Kodai No Sekiban??

If yes, is it only possible to boot genuine BS-X rom or it can load them from eprom cart?