SNES lockout disabled detection

[Fisher]

Hello.
I know some special SNES chips, like the SA-1 and SDD-1 can detect if the lock inside the console is disabled.
Is there a way to disable or trick this check other than installing a lock chip inside the cartridge?

[Ziggy587]

For the S-DD1, I remember reading that you can disconnect a single pin on the cart edge connector and that would let the cart boot on a console with a disabled lockout chip. I remember seeing this years ago, but I can't seem to find the page in Google right now.

edit: I still can't find the page, but I had the info saved on my PC. There's two methods. One, lift pin 86 on the S-DD1. The easier (and more easily reversed) method is to block a pin on the edge connector with a piece of tape. If you follow this cart edge pinout, it's pin 56. My suspicion is that cart edge pin 56 in connected to S-DD1 pin 86, so either method gives the same result, but I don't have an S-DD1 cart in front of me to confirm.

There are some important notes though. Blocking this pin will keep the cart from being able to boot on a stock (unmodified) console. The author also states that "it will not always load on the first try but it will load more often than not."

Usually people don't simply disable the lockout chip in the SNES for this reason, they install a switch so you can turn it on and off. Also, another option would be installing the SuperCIC in the console.

I don't know about the SA-1, but you could try blocking cart edge pin 56 and seeing if it works.

[Fisher]

Thanks for the info!
Unfortunately, after I taped my Kirby Super Deluxe cart it kept not booting on a lock disabled SNES.
I think I had an SFA2 cartridge but I just can't find it now, maybe some friend borrow it about 20 years ago and neither me nor him remember.
I'm asking this because most SNESes sold here in Brazil back on the day had the lockout disabled.
So when I try any of these games on other consoles most of the time I get a black screen. For this reason I would like to mod the cartridge instead of the console.

[lidnariq]

My suspicion is that cart edge pin 56 in connected to S-DD1 pin 86, so either method gives the same result, but I don't have an S-DD1 cart in front of me to confirm.

Yes, you're correct. (my updated copy of siudym's S-DD1 pinout).

[nocash]

I had somehow missed the S-DD1 pinout (adding it to next fullsnes.htm version). Thanks!

[Fisher]

That's interesting.
It seems that the whole ROM is accessed only through the chip, at least on the SDD1's case.
How does it stop booting if the lockout disable is detected?
Pulling the ROM /CE high?
Any chance of these chips be 3,3V tolerant?

[lidnariq]

"All data via the coprocessor" is actually the usual way it works on the SNES. (The DSP-1 is an exception)

The S-DD1 is responsible for relaying all data, so "how" it locks out the ROM after a CIC fail is somewhat immaterial—it could lock out arbitrary other features as well.