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PostPosted: Wed Nov 02, 2016 9:38 pm 
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I recently found this Famiclone cartridge for sale: https://www.aliexpress.com/store/produc ... 92686.html

Now, if it really does contain all the games listed, that's an amazing lineup to get for such a low price. But in the buyer feedback section, someone posted a picture of the cartridge's PCB: https://ae01.alicdn.com/kf/UT8xxa7XJ8XXXcUQpbXC.png

Looking those part numbers up, I found that those are all low voltage (3V) parts. I don't know much about electronics, but isn't using 3V parts in a 5V system a really bad idea? What kind of problems should one expect when playing cartridges like this one? Will any possible damage be limited to the cartridge or could it affect the console as well?

I wonder if the Famiclone cartridges I bought 10+ years ago suffer from this (possibly) terrible design decision. I used to play them all the time on my Dynavision Famiclone without problems, though.


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PostPosted: Thu Nov 03, 2016 3:31 am 
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The Kira Kira Star Night homebrew carts did that, and they didn't boot on real NESs, and IIRC fried some. Going off memory, check the frying.


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PostPosted: Thu Nov 03, 2016 3:25 pm 
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The 8-bit Music Power cart did not run on anything earlier than a Famicom AV. The Kira Kira Star Night DX cart seems to run on just about anything.

Interesting that Kirby's Adventure is on the cart, the cart does not look like it has a battery for saving games.

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PostPosted: Thu Nov 03, 2016 4:33 pm 
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tokumaru wrote:
Looking those part numbers up, I found that those are all low voltage (3V) parts. I don't know much about electronics, but isn't using 3V parts in a 5V system a really bad idea? What kind of problems should one expect when playing cartridges like this one? Will any possible damage be limited to the cartridge or could it affect the console as well?
Because the NES is NMOS, its output pullup drivers are NMOS, and not very good at sourcing current. So being loaded with 3V logic should work out ok for the 2A03 and 2C02.

(3.3V logic + 0.7V diode drop from overvoltage diodes on said logic + ≈1V threshold voltage for the n-type MOSFETs = very minimal current loading on the NES's output drivers)

On the other hand, that ROM shouldn't like being operating with a 5V supply instead of a 3V supply... so it ought to fail eventually.


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PostPosted: Thu Nov 03, 2016 8:11 pm 
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Great Hierophant wrote:
Interesting that Kirby's Adventure is on the cart, the cart does not look like it has a battery for saving games.

There are 2 versions of the cartridge, the one that can save has its own listing. Kirby's Adventure seems to be messed up in this cartridge though. There are palette and pattern issues according to a review containing screenshots.

lidnariq wrote:
Because the NES is NMOS, its output pullup drivers are NMOS, and not very good at sourcing current. So being loaded with 3V logic should work out ok for the 2A03 and 2C02.

(3.3V logic + 0.7V diode drop from overvoltage diodes on said logic + ≈1V threshold voltage for the n-type MOSFETs = very minimal current loading on the NES's output drivers)

On the other hand, that ROM shouldn't like being operating with a 5V supply instead of a 3V supply... so it ought to fail eventually.

Thanks for the explanation.

My copy of the cartridge arrived today. I don't know why I bought it, since I could easily play any of these games using a Flash cart, but since I have a small Famiclone collection this seemed like a nice addition. I tested it on the Dynavision only, not sure if I'll ever try it on an official NES or Famicom. The game list is 100% accurate, there are no repeats or weird hacks. Most games appear to work fine, at least the little bit I played of each one, but Kirby does indeed show the problems that were pointed out in the review.


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PostPosted: Sat Nov 05, 2016 3:20 pm 
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This is one of those dealies with a Flash ROM, multi-MMC3 mapper, and a 3V CHR-RAM chip? Someone tried running those on a NES once, and couldn't get any working graphics due to the voltage differences.

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PostPosted: Sat Nov 05, 2016 3:32 pm 
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If there are transceivers on the back (or inside the glob top) then it should work fine. Otherwise it might get broken or eventually fried in very rare cases (if that will work at all)


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PostPosted: Sat Nov 05, 2016 10:31 pm 
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I'm too afraid to try it on any of my NESes, and even more so on my Famicom AV. Works just fine on my Famiclone, though. The very first boot took a while, it showed nothing but a black screen for a period long enough for me to think it wasn't working. After trying a couple of times I decided to wait and the menu eventually showed up (something between 5 and 10 seconds, maybe). Subsequent resets were much faster, but I don't think I tried another cold boot yet.


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