Disabling NES lockout chip

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NESBest
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Disabling NES lockout chip

Post by NESBest » Sun Jun 25, 2006 8:16 pm

hey, i'm disabling my NES lockout chip but i would like it to be switchable between being on and off. To do this i need to wire a switch so that pin 4 is both hooked up to its original spot on the board, and 0V(ground) which is one of the other pins, i beleive pin 12-14 are ground. my switch has two positions, on the side it says ON ON, it has 3 poitns on the bottom, i beleive its an SPDT switch. However, i am a bit confuzed on how to wire this, anyone have ne words of advice or diagrams?

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Klefmung
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Post by Klefmung » Sun Jun 25, 2006 8:34 pm

I think you can attatch pin four to the middle pin of the switch and ground to one of the others. Then I think that will decide whether attatching pin four to the ground or nothing.
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Post by NESBest » Sun Jun 25, 2006 9:29 pm

having it decide whether its ground or nothing would make it do the same thing, i need it so it decides ifits ground or 5v

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Post by gannon » Sun Jun 25, 2006 9:37 pm

Just use a spst switch inbetween the pin and the board contact, it has an internal pulldown so it doesn't need to be tied to ground IIRC

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NESBest
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spdt switch

Post by NESBest » Sun Jun 25, 2006 9:43 pm

i think my switch is SPDT it has two positions and both say on, i've used it before as an on off switch so could i use it for this mod

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NESBest
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testing/is my diagram correct

Post by NESBest » Sun Jun 25, 2006 9:53 pm

Image

http://www.uploadfile.info/uploads/7e2083d577.jpg

those are my rough diagrams of how i thought i could wire this thing up

i also want to test out if the mod is working correctly so i decided to take the lockout chip out of a cartridge that i have doubles of

Image

http://www.uploadfile.info/uploads/b4657994a0.jpg

is the small IC on the right the cartridges lockout chip?

thanx for all the help

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Post by MM007 » Mon Jun 26, 2006 10:12 am

Yes. The small chip is the "key" chip used to confirm to the lockout chip that the console works. The other two chips are the CHR ROM and PRG ROM, which contain the game data.

Before going to the trouble of prying this game chip off of the cartridge, there is a way to test if the lockout chip is deactivated first.

Turn on your NES without a game pack inside of it, and with the switch in the lockout chip disable position. The NES on LED and the TV screen should NOT flash. If they do, the lockout chip is still operational. n short, if the NES does the same thing regardless of switch position when turned on without a game, you screwed up. If it flashes when the chip is activated and doesn't when the chip is deactivated, you got it right so far and gan move to using a modded NES cartridge.
Warranty-Voiding fun!

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NESBest
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Post by NESBest » Mon Jun 26, 2006 7:31 pm

thanks a lot for the advice on testing it, i was just wondering if the "diagram" i drew is correct for wiring a switch, or if anything should be switched or removed, its up a little bit but if you'd rather not scroll
http://www.uploadfile.info/uploads/7e2083d577.jpg
there you go

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Post by Klefmung » Mon Jun 26, 2006 7:46 pm

NESBest wrote:having it decide whether its ground or nothing would make it do the same thing, i need it so it decides ifits ground or 5v
It is already connected to 5v though. So you will just have to decide whether ground or nothing. >_> Mortals....
gannon wrote:hmm... *ponders about power abuse* :P
benheck wrote:Wow, guess I should have searched my own forums! Oh wait, I don't have to since the rules don't apply to me ;)

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Post by NESBest » Mon Jun 26, 2006 11:15 pm

hey i finished the lockout mod and under the no cartridge test it works perfectly with the switch, tho what i assumed would be off was on, oh well it works, thanks to everyone who helped

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