Famicom Pocketgames 150in1 (3.3V - 5V)

Started by khchonh, August 17, 2017, 05:55:06 am

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khchonh

Hello!
What should I solder to improve the cartridge?
Resistor, transistor or what? What quantity? Where to solder?
On this cartridge 3.3 volts or 5 volts?



jpx72

I believe there are people who know more, but recently I was "repairing" such cart and I only have cut the trace between the two very small soldering spots just on the left of the place where the diode soldering pads are.

But on other cart a diode in that place worked allright.

Great Hierophant

I wouldn't expect that cartridge to last very long in a real system, best use it on a clone.  There are no pads for a voltage regulator, no space for resistors and one diode is not going to be enough.
Check out my retro gaming and computing blog : http://nerdlypleasures.blogspot.com/

FAMICOM_87

I have a similar one , really is there a way to step down 5V to 3.3V in this PCB layout  :upsetroll:

Great Hierophant

It looks like, at best, they are using a resistor to cut the voltage down.  I'm sure that is a wretched design.
Check out my retro gaming and computing blog : http://nerdlypleasures.blogspot.com/

krzy

I think that adding zener diode will cause more harm than feature - cause when powered by 5V, the memory won't clamp the voltage on input pins to 3.3V, not causing excessive current consumption (as opposed to powering from 3.3V).
So without zener you only risk destroying the cartridge sooner or later, while with zener - probably also the console.

FAMICOM_87

Quote from: krzy on November 11, 2018, 04:33:56 am
I think that adding zener diode will cause more harm than feature - cause when powered by 5V, the memory won't clamp the voltage on input pins to 3.3V, not causing excessive current consumption (as opposed to powering from 3.3V).
So without zener you only risk destroying the cartridge sooner or later, while with zener - probably also the console.

So at least our consoles are save ?  :fire: :redcart:
What about your idea and project for an adapter with step down converters, is it finished yet :) ?  ??? :D

krzy

Quote
So at least our consoles are save ?

I don't have idea how those chips behave when 5V power supply is applied to them as well as 5V logic sygnal. It might depents on the manufacturer, this is not something that they are designed to, so i wouldn't assume that any of that is safe.


Quote
What about your idea and project for an adapter with step down converters, is it finished yet Smiley ?

Yea, I made a few pieces of the adapter and it works and it protects console, but I am not sure if somebody would be interested in buying it. Maybe if I would integrate game genie with it, there would be more people willing to buy it.

FAMICOM_87

very cool! :) it will be the saver for those china  :redcart: :fire: with great games and poor PCB designs  :crazy: 

80sFREAK

Ok... Here is my input on this case...

75...100 Ohm resistors on signal lines should work as current limiters to keep both cart and console safe. I have no idea about mapper(5V tolerant or not), so all signal lines.
I don't buy, sell or trade at moment.
But my question is how hackers at that time were able to hack those games?(c)krzy

FAMICOM_87

Quote from: 80sFREAK on November 12, 2018, 08:24:49 am
Ok... Here is my input on this case...

75...100 Ohm resistors on signal lines should work as current limiters to keep both cart and console safe. I have no idea about mapper(5V tolerant or not), so all signal lines.

can you make a scheme where to put those resistors, so we can make an adapters or cutting traces and add them that way   :crazy:

VegaVegas

Modifying this existing cart pictured above would be the worst nightmare, in fact it's not even possible in any way. The game genie sort of adapter transceiving 3V-5V is the only way to go here

FAMICOM_87

Quote from: MaarioS on November 22, 2018, 03:11:03 pm
Modifying this existing cart pictured above would be the worst nightmare, in fact it's not even possible in any way. The game genie sort of adapter transceiving 3V-5V is the only way to go here

OK, but on witch pads to put resistors?  ::)

80sFREAK

November 23, 2018, 01:00:58 am #13 Last Edit: November 23, 2018, 01:09:18 am by 80sFREAK
All of them, except groung and +5V. added No need resistors on sound lines :)
I don't buy, sell or trade at moment.
But my question is how hackers at that time were able to hack those games?(c)krzy

FAMICOM_87

Quote from: 80sFREAK on November 23, 2018, 01:00:58 am
All of them, except groung and +5V. added No need resistors on sound lines :)

Thanks  :D
So resistors on all PRG's  and CHR's expect VCC's GND's
What about pin 15 (IRQ) , pin 32 (M2) and pins 45 and 46 (EXP) ?
:-[

:redcart: