A31721-ND ptich problem

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K_Devel
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A31721-ND ptich problem

Post by K_Devel »

I read in numerous places that the slightly off pitch wouldn't be a problem using this slot as a replacement for the NES, but looking at the pins and an NES cart this problem is accumulative and is absolutely a problem causing the cart insertion to cross pins, While getting the pins of the slot connected to the NES is easy enough, the games will cross pins. I am wondering how could this slot be so recommended if this is a problem that would make a game unplayable? Is there something I'm missing here with this part? It just seems completely unusable. I was trying to not cannibalize my Game Genie, but it looks like this is the best option, I can pick up a new one this weekend probably. I've also had success in using the system end of an old original 72-pin ZIF by cutting it off and trimming it appropriately.

Is there any places like digikey that sells a viable edge connector w/ the 2.50mm pitch we need? I cannot find anything for the life of me, everything is 2.54mm.

on a side note, I've been looking for a viable slot for Famicom too. I'd rather NOT use my famicom adapter, but heck.. I don't wanna experience more pitch issues. I seem to never see any viable slots with mounts built on it either, not sure if anyone has a source they know of that sells such things other than bulk suppliers.

Thanks :)
tepples
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Re: A31721-ND ptich problem

Post by tepples »

Can you break the connector in the unused expansion area in the middle, shave off about 0.7 mm (18 pins worth of difference), and glue it back together? Then at least the errors won't accumulate from the PRG side of the edge connector to the CHR/CIC side.
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K_Devel
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Re: A31721-ND ptich problem

Post by K_Devel »

Hmph, I ended up cannibalizing the game genie because I didn't like that solution. I'm concerned for the integrity of the connector and my ability to dremel it in half and not screw it up lol. I bought another game genie today to replace it anyways. Thank you. :)
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Memblers
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Re: A31721-ND ptich problem

Post by Memblers »

I can report that my experience with the connector has been surprisingly good. I installed it on my NES, bending the pins 90 degrees so it's now sort of a top-loader. Of the 20 or so carts I had sitting nearby, every one of them worked on the first try. That includes sliding them towards either side of the connector. This includes some unlicensed carts, by AVE, Codemasters, and boards I've made. Except for a dead Punchout cart, but it doesn't work on anything.

Looks like it's not perfect though, the Game Genie I normally use works on it. But I stuck a different Game Genie onto an unsoldered connector and did a continuity check, and was detecting some shorted pins. I haven't stuck that particular GG into my NES yet. For some reason there actually are a bunch of Game Genie board variations that are slightly different (apparently including edge pin spacing and placement). Also, my lockout chip is disabled by a switch, so it's possible I've missed out on that error during some tests (they are among the affected pins).

If there was a source for a 2.5mm connector, I'd be interested as well, maybe even a bulk buy if needed.

BTW, I believe the pin pitch on Famicom actually is the standard 2.54mm.
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K_Devel
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Re: A31721-ND ptich problem

Post by K_Devel »

Memblers wrote:I can report that my experience with the connector has been surprisingly good. I installed it on my NES, bending the pins 90 degrees so it's now sort of a top-loader. Of the 20 or so carts I had sitting nearby, every one of them worked on the first try. That includes sliding them towards either side of the connector. This includes some unlicensed carts, by AVE, Codemasters, and boards I've made. Except for a dead Punchout cart, but it doesn't work on anything.

Looks like it's not perfect though, the Game Genie I normally use works on it. But I stuck a different Game Genie onto an unsoldered connector and did a continuity check, and was detecting some shorted pins. I haven't stuck that particular GG into my NES yet. For some reason there actually are a bunch of Game Genie board variations that are slightly different (apparently including edge pin spacing and placement). Also, my lockout chip is disabled by a switch, so it's possible I've missed out on that error during some tests (they are among the affected pins).

If there was a source for a 2.5mm connector, I'd be interested as well, maybe even a bulk buy if needed.

BTW, I believe the pin pitch on Famicom actually is the standard 2.54mm.
Good news for Famicom, I'll get that sorted ASAP. The problem with the digikey edge connector isn't so much the pins on the bottom but the contacts on the inside. I even put a cart up to it to kinda get a peek of what the problem was. I saw possible (likely) crossover between board contacts and edge connector pins. I automatically ditched the idea of these being useful. Lemme try to provide a visual you can see. Game Genie connector is where I'm going with this now because after I hooked this up the games just did NOT load. Kind of a shame, I liked the idea of using a new edge connector rather than cannibalizing one.

Thanks for the information.

Image
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