The Dangers of using 3.3V Flash Carts in Retro Consoles

Joe Redifer · 07/05/2017, 05:28 PM

Rene of dbelectronics has posted an article on his site about possible dangers of using flash carts with your system. Some are fine, others are not. Worst are multicarts.

His article is here:
wayback://db-elec/dangers-of-3-3v-flash-in-retro-consoles/

Quote from: ReneThe use of 3.3V flash in retrogaming can lead to serious problems. Following a lengthy podcast discussion on the subject I felt it was important to elaborate on the matter by:

Giving technical explanations of the problem
Addressing common rebuttals
Listing devices which exhibit this problem

Let me be clear that using 3.3V Flash in a 5V system in of itself is not inherently bad; it can be done properly using level translators such as what has been done with the SD2SNES. What is bad, and what I am speaking out against, is directly connecting 3.3V Flash to 5V buses without proper interfaces such as level translators.

The 2nd version of the Turbo Everdrive is fine. The original isn't. Of course I have the original. Looks like I'll have to rebuying newer revisions of some carts and I hope Krikzz updates some of the others which have no good revisions, like Mega Everdrive X7, Master Everdrive etc etc. Apparently the Darksoft Neo Geo SD thingy is good. Not sure about the NeoSD.

NecroPhile · 07/05/2017, 05:48 PM

I can't say I understand much of the (lengthy) article, but I'm pretty sure my TED is a 2.x. I should be safe, I guess.

I don't use it much, but what about the neoflash ones?

Quote... I'm also French which means I'm an asshole as well!

esteban · 07/05/2017, 05:50 PM

Quote from: NecroPhile on 07/05/2017, 05:48 PMI can't say I understand much of the (lengthy) article, but I'm pretty sure my TED is a 2.x. I should be safe, I guess.

I don't use it much, but what about the neoflash ones?

Quote... I'm also French which means I'm an asshole as well!

UPDATE: Crap, I'm pretty sure I have TED 1.2. Goddammit.

The TED 2.0 has fancy text and I don't remember fancy text.

What are the chances that Gameofyou or NEOFLASH (as NecroPhile mentioned already) are kosher?

jtucci31 · 07/05/2017, 06:20 PM

Well shit, I have my V1 ED going strong. I'll have to read this article more when I get home.

Even worse is that I can't sell this one knowing I'll be giving someone else potential problems. Bummer.

esteban · 07/05/2017, 06:23 PM

Quote from: guest on 07/05/2017, 06:20 PMWell shit, I have my V1 ED going strong. I'll have to read this article more when I get home.

Even worse is that I can't sell this one knowing I'll be giving someone else potential problems. Bummer.

I think we can sell them as "collector's item only—not for use"

I'm going to wait 10-15 years...

o.pwuaioc · 07/05/2017, 06:23 PM

"Sell everything and get a flash cart," they said. "It'll be fun," they said.

jtucci31 · 07/05/2017, 06:27 PM

Maybe I can do a special group buy for the first group I did where we all got the V1

CrackTiger · 07/05/2017, 06:34 PM

TED v2+ have compatibility issues with mods (and seemingly various stock models) and different levels of success playing various sound files.

If this guy knows what he's talking about (people have reported problems with his own products), then what's important to know is what exactly could be damaged and what would the repair involve.

Old hardware needs service whether you use it or not. The trade off for what these flash carts provide is still worth it. Especially for consoles which are still relatively cheap to buy.

esteban · 07/05/2017, 06:40 PM

Quote from: guest on 07/05/2017, 06:34 PMTED v2+ have compatibility issues with mods (and seemingly various stock models) and different levels of success playing various sound files.

If this guy knows what he's talking about (people have reported problems with his own products), then what's important to know is what exactly could be damaged and what would the repair involve.

Old hardware needs service whether you use it or not. The trade off for what these flash carts provide is still worth it. Especially for consoles which are still relatively cheap to buy.

I will trade you TED v2+ for my V1.2 (?) V1.3(?)

(I'm out with the kids)

SRSLY.

CGQuarterly · 07/05/2017, 06:40 PM

I saw this when it was posted on Reddit. Maybe I didn't read carefully enough, but how many documented cases of these products causing problems have their been? I understand that some EDs may be bad in theory, but have there *actually* been any problems?

esteban · 07/05/2017, 06:46 PM

Quote from: CGQuarterly on 07/05/2017, 06:40 PMI saw this when it was posted on Reddit. Maybe I didn't read carefully enough, but how many documented cases of these products causing problems have their been? I understand that some EDs may be bad in theory, but have there *actually* been any problems?

I'll trade your TED 2 for my TED 1.3.

Thank you.

CrackTiger · 07/05/2017, 06:49 PM

I kept my TED 1 after buying a TED 2 because you need both to play everything and on everything.

crazydean · 07/05/2017, 06:52 PM

Quote from: guest on 07/05/2017, 06:34 PMOld hardware needs service whether you use it or not. The trade off for what these flash carts provide is still worth it. Especially for consoles which are still relatively cheap to buy.

This was my thoughts on the matter. While a modded PCE Duo is $300, a Genesis goes for less than $50. I don't play it all that much and if it goes in 5 years, I'll get another one. I figure we'll all be using virtual screens that are implanted into our brains by then anyway.

SignOfZeta · 07/05/2017, 08:42 PM

As the flash cards started to multiply and cover the earth we would hear stories about how certain systems (maybe US Turbo?) couldn't seem to provide the current the flash card needed. This never sounded good...Thanks to this guy taking the time to go over many boards we now know it's because people who make flash cards in general apparently think it's OK to ignore the spec sheets of the componants they are reselling. If this were a "real" consumer product that would be a bunch of problems. Considering the numbers of these things moving nowadays I'd say it's irresponsible for the makers of flash cards to do this and not tell the customer about it.

I agree, it's a valid point, the world could lose 100,000 SNES systems to shitty flash card designs and it wouldn't really matter. Some of these flash cards are more expensive than the system they run in. I would worry about a Neo or something though. Duos...probably not a great idea, Turbografx 16...hm...I think we found a use for the giant POS TG-16, sacrifice it to the flash cards!

CrackTiger · 07/05/2017, 08:50 PM

I'm not worried about the NeoSD because of the extreme knowledge they have of the hardware and dedication to perfection. The price would be justified even if it wasn't the highest quality flash cart. The Neo Geo multi-carts are well known to be problematic.

It's true that some flash carts cost more than the hardware, but that's pretty much meaningless. None cost more than the libraries they support.

Johnpv · 07/05/2017, 09:13 PM

Quote from: CGQuarterly on 07/05/2017, 06:40 PMI saw this when it was posted on Reddit. Maybe I didn't read carefully enough, but how many documented cases of these products causing problems have their been? I understand that some EDs may be bad in theory, but have there *actually* been any problems?

I don't understand posts like this. If some one told you running a certain type of gasoline had a chance of ruining your engine would you do it just because no one else had that problem? When there's a recall on your car do you not get it done because no one you know has had the problem? To quote his article this is a great response

Quote"Well, my device has been working properly for 2 years now."
This is like saying: "I've been smoking for 2 years and I don't have cancer. Therefore, smoking does not cause cancer." If you believe this statement, you deserve to damage your retro console.

While there aren't specific documentations of everdrives killing TG16s or Super Nintendos there are documented cases of the 150 in 1's killing NES' and the MVS 161 in 1s killing plenty of MVS boards. Plus how many consoles have died with people not knowing the reason to blindly attribute it to an everdrive you never thought would be an issue. Unless someone was specifically looking for this it'd be hard to know over the last few years how many people it's happened to.

Rene knows his shit, and I've never seen issues with his products, some with the chinese knock offs of his stuff but not with his particular products. IMHO the reaction should be less to be blaise about the issue and hope for Krikzz and the maker of similar products to update their designs and release a better product.

I'm glad someone brings this stuff to light, same with Voultar's recent video about the issues with Retro_Console_Accessories Genesis RGB cables and the boosted sync amp in them.

SignOfZeta · 07/05/2017, 09:35 PM

There no question that running components outside of their rated capacity is a half-ass measure unless you are building an F1 car or some other such bleeding edge stuff. The OEM would never spec a cart that draws this much so I don't see why it's acceptable for someone claiming to sell a quality product.

However, if your $175 flash card wastes a $35 system, who gives a shit? Especially since you "saved" so much money running flash cards in the first place.

Johnpv · 07/05/2017, 10:02 PM

Enough of those $35 systems get wasted and they're not going to be $35 systems any more.

SignOfZeta · 07/05/2017, 10:29 PM

I was being sarcastic. The $175 flash card that wastes systems is clearly crap and deserves to die long before a Genesis or whatever that's been doing its job, probably flawlessly, even with weird modems and staking carts and whatnot, for decades.

xcrement5x · 07/05/2017, 10:53 PM

I read the article and was having a hard time fully understanding which components in a system are actually being damaged by the higher 5V. I can understand the wear on the cart (since it's taking more voltage than originally specified), but can someone explain this better?

Quotehttps://db-electronics.ca/2017/07/05/the-dangers-of-3-3v-flash-in-retro-consoles/#What_Damage_Can_Be_Caused

Prolonged use of components outside of their specified tolerances inevitably leads to failure. On the console side, the stress is excessive current output on digital outputs when driving a logic high. On the cartridge side, the stress is excessive heat dissipation due to conduction of the clamping diodes. I have already heard from several friends that their NES consoles have died most likely due to their admittedly heavy use of cheap multicarts. These are particularly bad. I would avoid these like the plague. I suspect poorly designed Everdrives will require more time before we start seeing failures.

What does this mean? Does it impact the voltage regulators which convert the power source in to 5V normally? Or something else on a given board?

Gypsy · 07/05/2017, 11:09 PM

Well I know what should but also won't happen here. Krikzz should fix this shit at cost.

What sound do we hear when he would be asked to do this? Kricketzz.

Quote from: SignOfZeta on 07/05/2017, 09:35 PMThere no question that running components outside of their rated capacity is a half-ass measure unless you are building an F1 car or some other such bleeding edge stuff. The OEM would never spec a cart that draws this much so I don't see why it's acceptable for someone claiming to sell a quality product.

However, if your $175 flash card wastes a $35 system, who gives a shit? Especially since you "saved" so much money running flash cards in the first place.

CrackTiger · 07/05/2017, 11:13 PM

Quote from: Johnpv on 07/05/2017, 09:13 PMIMHO the reaction should be less to be blaise about the issue and hope for Krikzz and the maker of similar products to update their designs and release a better product.

I'm glad someone brings this stuff to light, same with Voultar's recent video about the issues with Retro_Console_Accessories Genesis RGB cables and the boosted sync amp in them.

Everyone is glad to be tipped off to potential problems, but these guys made videos strictly for tech experts and the rest of us are still waiting to find out what a flash cart would actually damage if it ever happened and specifically what kind of cables are considered "boosted".

Remember that playing real carts and CDs leads to your cart ports and CD drives, plus other important parts to wear out or break down.

Gypsy · 07/05/2017, 11:25 PM

I'll admit the video was a bit frustrating for me. I found it much more easier to read the article from the DBE guy.

What can actually happen if something goes wrong with that cable? I've had and used one for years now. Including being fed to two different things (pvm and dvdo processor) and never had any issues. It was never directly plugged into the display though, as I had to use a break out cable. So yeah maybe someone smarter than me can answer it simply, what could go wrong using the cable as-is?

CGQuarterly · 07/06/2017, 01:06 AM

Quote from: esteban on 07/05/2017, 06:46 PMI'll trade your TED 2 for my TED 1.3.

Thank you.

I have the original TED.

Quote from: Johnpv on 07/05/2017, 09:13 PM
Quote from: CGQuarterly on 07/05/2017, 06:40 PMI saw this when it was posted on Reddit. Maybe I didn't read carefully enough, but how many documented cases of these products causing problems have their been? I understand that some EDs may be bad in theory, but have there *actually* been any problems?
I don't understand posts like this. If some one told you running a certain type of gasoline had a chance of ruining your engine would you do it just because no one else had that problem? When there's a recall on your car do you not get it done because no one you know has had the problem?

Dude, in my 40 years on this earth, scientists have gone back and forth countless times on whether or not it's OK to eat eggs, eat butter, drink wine, etc. etc. MTBE is OK; MTBE is not OK. It's fine to spray DDT in people's faces, oh wait no it causes reproductive problems. I get that in theory these devices are not optimized for the hardware on which they are running. Comparing this to a car recall is ridiculous. We're talking about video games. Wake me up when peoples' systems actually start taking shits en masse and maybe I'll care.

Gypsy · 07/06/2017, 01:10 AM

The point is more that this is an easy enough fix to implement, that wouldn't even cost much. Especially given the massive premium that Kricketzz charges.

Also, isn't it better to catch it before systems die off in bulk? Obviously in the scheme of things, it's just video games but this goes back to the premium product + easy fix point.

SignOfZeta · 07/06/2017, 01:21 AM

It's bad design, period. If someone builds a house for four with a heating system from a one bedroom apartment there are consequences.

Also, it's not something like eggs being good/bad for you. Humans and eggs don't have spec sheets. Nobody knows WTF is really going on with natural organisms. These flash chips have spec sheets from their actual manufacturers that say, flatly, that 5V is too much. It would be like if God himself sent an email to you that said, "eat one egg a day". These are cheap ass designs by questionable people. There is no interpretation. You don't put ten lbs of sausage into a five pound sack.

ClodBusted · 07/06/2017, 01:42 AM

Even without having clicked the link from Joe yet, I can guess from the posts here in this thread that the problem is as simple as Ohm's law. Feed a component (flash cart) more voltage than it was designed for, then it will draw more current from the device (console), than both the component as well as the device are designed for, resulting in heat and thus damage.

SignOfZeta · 07/06/2017, 02:13 AM

Quote from: guest on 07/05/2017, 10:53 PMI read the article and was having a hard time fully understanding which components in a system are actually being damaged by the higher 5V. I can understand the wear on the cart (since it's taking more voltage than originally specified), but can someone explain this better?

Quotehttps://db-electronics.ca/2017/07/05/the-dangers-of-3-3v-flash-in-retro-consoles/#What_Damage_Can_Be_Caused

Prolonged use of components outside of their specified tolerances inevitably leads to failure. On the console side, the stress is excessive current output on digital outputs when driving a logic high. On the cartridge side, the stress is excessive heat dissipation due to conduction of the clamping diodes. I have already heard from several friends that their NES consoles have died most likely due to their admittedly heavy use of cheap multicarts. These are particularly bad. I would avoid these like the plague. I suspect poorly designed Everdrives will require more time before we start seeing failures.
What does this mean? Does it impact the voltage regulators which convert the power source in to 5V normally? Or something else on a given board?

Basically, electronic circuits are designed with a balance. If you have 5V pushing a motor you're expecting the motor to consume a certain about of current if you put a 3V motor in its place it...may spin faster, for a while, but even if it doesn't fall apart from going too fast it will eventually fail from excessive current that it can't use.

With data, I admit I'm not as experienced as I am with more conventional electrical loads. However the concept is the same. You now have less impedance than a normal cart. Therefore the 5V is going to push more current through the flash than the flash is rated for. But it will not only put more through the flash than it expects but you are flowing more current THROUGH THE ENTIRE CIRCUIT (as always, current flow through a circuit is the same everywhere), most of which Sega made, which means your poor Genesis is now being asked to supply more amps than it was supposed to but it's also experiencing that over-current through...well, exactly what I'm not sure, and it depends on the system, but I think its possible you could lose RAM, CPU, or anything else that lives on the cart bus.

This news isn't going to stop me from using flash carts but it does make me kinda not want to buy any more until they start designing entire projects instead of just wiring flash directly to your cart slot. This has less to do with reliability and more to do with just not wanting to support hacks.

ClodBusted · 07/06/2017, 02:46 AM

The thing is, these flashcart designers could have easily dropped in a series resistor acting as a simple voltage divider. Just as you do with simple DIY LED applications to prevent them from being damaged through overcurrent.
Or have a proper voltage regulator.

This is nothing fancy, pretty much everybody who attended electronics class at school once built a voltage divider.

-----

By the way, Joe: Thank you very much for making aware of the article you linked, I'm reading it right now. I'm shocked to see some flash carts neglecting even the simplest princliples of good basic electronics design, and I'm not even talking about correct voltage levels but also other things that upset me (no proper ground planes, etc.).

-----

I will take a closer look at my gamingenterprisesinc LowCost Flash HuCard. Quite a coincidence my Turbo Duo died a few days after I had the cart inserted for the first time...

SignOfZeta · 07/06/2017, 02:57 AM

Would just a resister work? I don't think it's that simple, but regardless, it's clearly achievable.

ClodBusted · 07/06/2017, 03:23 AM

Voltage divider:

Not as sophisticated and stable as a true voltage regulator (regardless of old style linear regulator or modern style switched regulator), which is much better suited for a wide range of input voltages and shifting loads.

But it will work if these criteria are met:
V-input stays constant and predictable all the time.
R1 (series resistor) is physically sized to take up the heat (Wattage) that occures in the voltage drop.
R2 (flash cart) stays constant in value all the time time.

TR0N · 07/06/2017, 03:24 AM

Have the latest TED so i'm good.I have thought about selling my old everdrive md to buy the latest model.

SignOfZeta · 07/06/2017, 03:44 AM

Quote from: guest on 07/06/2017, 03:23 AMVoltage divider:

Not as sophisticated and stable as a true voltage regulator, which is much better suited for a wide range of input voltages and shifting loads.

But it will work if these criteria are met:
V-input stays constant and predictable all the time.
R1 (series resistor) is decent sized enough to take up the heat that occures in the voltage drop.
R2 (flash cart) stays constant in value all the time time.

Yes, but would it cause issues on a data bus ? He's saying there should be level translator ICs in there, he never speaks of simple regulation or load. The 5V stuff has to read and write at 5V and the 3.3V stuff has to read and write at 3.3V. Also, data lines have almost no current consumption so resistors barely work the same way as they do with a light or a heater or a motor or something.

ClodBusted · 07/06/2017, 06:18 AM

Why should this cause issues?

EDIT: I have now read the linked article, and from what I can see, some Everdrives that are rated as "bad/avoid" actually use series resistors to drop the voltage.

1. So am I correct in the assumption that the resistors chosen are not the correct resistance value?
2. Does the author of the article generally dismiss series resistors, in favor of proper voltage level translation using semiconductors?

Johnpv · 07/06/2017, 06:31 AM

Quote from: CGQuarterly on 07/06/2017, 01:06 AMDude, in my 40 years on this earth, scientists have gone back and forth countless times on whether or not it's OK to eat eggs, eat butter, drink wine, etc. etc. MTBE is OK; MTBE is not OK. It's fine to spray DDT in people's faces, oh wait no it causes reproductive problems. I get that in theory these devices are not optimized for the hardware on which they are running. Comparing this to a car recall is ridiculous. We're talking about video games. Wake me up when peoples' systems actually start taking shits en masse and maybe I'll care.

Yeah not even remotely the same. You're comparing apples to oranges. This isn't some doctors guessing at partial data it's a manufacturer specifically saying using voltages higher than 3.3v on this line will break things. Literally the manufacturer of the part is saying this is bad don't do this and you're still questioning it. It's like saying yeah my tires are only rated for 80 mph but until some one drives them at 160 and they blow that's what I'm going to do. Besides since no one was looking for this who knows how many systems these have killed.

sirhcman · 07/06/2017, 09:32 AM

Quote from: Johnpv on 07/06/2017, 06:31 AMIt's like saying yeah my tires are only rated for 80 mph but until some one drives them at 160 and they blow that's what I'm going to do. Besides since no one was looking for this who knows how many systems these have killed.

I'll take a dead system over a blowout at 160 mph any day of the week. It's all about perspective.

NecroPhile · 07/06/2017, 09:52 AM

I checked my TED and it's a version 2.2. I'm good to go!

Sorry if I missed it, but I didn't see anyone answer if the neoflash is safe or not.

Also, I didn't see an answer to just what is ruined. It's all well and good to say systems are being "killed", but there's a big difference between a system with a melted pcb and all its components and one where a $3 voltage regulator dies after 5 years of heavy flashcart use or a system that needs new caps after 10 years instead of them lasting 30 years. I'm not saying it's okay to build shit wrong, of course, but some consequences are a lot more worrisome than others.

esteban · 07/06/2017, 11:33 AM

^ NecroPhile: Still no word on:
Neoflash (not that it matters)
gameofyou (only a handful of us have one, I think)

SignOfZeta · 07/06/2017, 11:39 AM

It's not going to be a voltage regulator. A regulator isn't going to care about such a small difference. The problem is that your CPU, your RAM, and anything that touches the flash is having more current pumped through it than normal.

Exactly WHAT will fail is anyone's guess, maybe nothing, but the parts at risk aren't common diodes and resisters, they are more important things like your CPU.

ClodBusted · 07/06/2017, 11:48 AM

Well said.

crazydean · 07/06/2017, 12:02 PM

I also want to hear about the NeoSD.

It's good that this information has come to light. Although, multi-carts have already been known to damage consoles. It will help us all make better decisions in the future. However, no one is saying what exactly is being damaged in these consoles. I assume every console model will have a different component fail since the weak link in every system is different.

With this news being made public and assuming the flash cartridge manufacturers don't change their designs, we will start seeing one of two things popping up:

1. Nothing will change because the amount of current isn't enough to actually damage the parts.
2. The repair guys will start putting out PSAs explaining the cause of the problem and how to fix it on a particular console model.

Also, please stop comparing the death of a gaming console to fucking cancer or a car crash. I would much rather lose all of my consoles than have cancer.

NecroPhile · 07/06/2017, 12:09 PM

Quote from: esteban on 07/06/2017, 11:33 AM^ Necro: Still no word on:
Neoflash (not that it matters)

Heh, that's accurate. I never use mine instead of the TED.

SignOfZeta · 07/06/2017, 12:10 PM

Quote from: guest on 07/06/2017, 06:18 AMWhy should this cause issues?

EDIT: I have now read the linked article, and from what I can see, some Everdrives that are rated as "bad/avoid" actually use series resistors to drop the voltage.

1. So am I correct in the assumption that the resistors chosen are not the correct resistance value?
2. Does the author of the article generally dismiss series resistors, in favor of proper voltage level translation using semiconductors?

Resistors only work when there is load in a system. RAM doesn't do any real work so whatever resistance value you put in there is basically meaningless. It's always going to be within a few mV of 5V no matter what the resistor is because RAM isn't designed to drop voltage. Of course, it *is* dropping more voltage now because some dipshit is using incompatible flash but logic chips should be all using the same voltage level to avoid as much switching trama as possible.

SignOfZeta · 07/06/2017, 12:12 PM

Quote from: esteban on 07/06/2017, 11:33 AM^ NecroPhile: Still no word on:
Neoflash (not that it matters)
gameofyou (only a handful of us have one, I think)

I think we can assume all cheap cards have this issue, including the French ones, the Canadian ones, all of Tobias's shit, most likely every repro.

I don't know if any of the cards you mentioned even work anymore (not mine!) but there are now 10x as many copies of Magical Chase as there used to be so I don't know about those...

o.pwuaioc · 07/06/2017, 12:19 PM

Quote from: CGQuarterly on 07/06/2017, 01:06 AMDude, in my 40 years on this earth, scientists have gone back and forth countless times on whether or not it's OK to eat eggs, eat butter, drink wine, etc. etc.

Actually, you mean the media have gone back and forth. The science generally doesn't make claims that large. Go and read the actual studies, and you'll see they're not as alarmist as others make them out to be.

xcrement5x · 07/06/2017, 12:58 PM

So, would it be possible to make a pass-through device (I am thinking about the Genesis specifically) that steps the 5V to the 3.3V and then passes that to the Everdrive to use? Or are there other parts of the Everdrive that specifically need the 5V and wouldn't work with a 3.3V instead.

sirhcman · 07/06/2017, 01:37 PM

I will wait to hear what thesteve says on the matter before dumping my TED v1

Johnpv · 07/06/2017, 02:11 PM

Quote from: crazydean on 07/06/2017, 12:02 PMAlso, please stop comparing the death of a gaming console to fucking cancer or a car crash. I would much rather lose all of my consoles than have cancer.

No one is comparing them in a level of issue. The point in the comparison is that lack of occurrence of something in a shortly poorly monitored time does not equal the thing never happening.

SignOfZeta · 07/06/2017, 04:03 PM

Quote from: guest on 07/06/2017, 12:58 PMSo, would it be possible to make a pass-through device (I am thinking about the Genesis specifically) that steps the 5V to the 3.3V and then passes that to the Everdrive to use? Or are there other parts of the Everdrive that specifically need the 5V and wouldn't work with a 3.3V instead.

As a matter of practicality, since this would only be needed to fix a shitty product more poorly made than itself, I don't see this happening. I guess it would depend on the system in question.

The reason he speaks of level modifiers instead of regulators or current limiting resistors is because it's really a much more delicate job.

(I really need to say, I am not an expert on electronics or semiconductors of this nature. My professional electronic experience is mostly automotive and I sorta know a few things about audio but that's about it. I think I understand the issue well enough to say this though.)

So let's say you have a 5V bus and a 3.3V flash cart. What happens?

The 3.3V chip would be overpowered. This is no problem. You can put a reg in there or even just a resistor, if you know all the hardware variations, since that actually would work for powering the chip. This has been done with most of these carts according to the video.

However, carts have lots of pins. The Neo has 256! Many are unused but regardless, there is more than just powering the chip to take care of. All the data lines on the bus (cart slot) are designed to send and receive at 5V.

Let's say, for example, that you had just one data out and one data in. They could be connected to the CPU, the RAM, the sound chip, some serial bus, whatever. Just consider that one is in and one is out.

So the data out on the bus is hooked to a data in on the flash. The flash basically watches that pin for a square wave, bits, like knocking on a door. This works fine, the flash will see the knocking on the door, but it will be REALLY LOUD, like that mouth breather who slams the door of your car so hard it shakes the entire parking lot. Now, if this were something a motor being overpowered it would just spin faster and make more heat and maybe waste it's bearings. The data input on a chip is super high impedance though. It may be 10KOhms or more. So the data outline is beating on the door like crazy but the door is made of concrete and isn't going anywhere.

Where does the voltage go? If current is high, as is the theory, then this chip is dropping voltages. Its dropping the same it normally does PLUS whatever extra voltages there is. Since the chip can only produce heat as a byproduct of switching this means that all the voltage drop is basically coming from arcing at the data lines.

Right? I think so. What makes connections arc is a difference in voltage between the two points. Connecting 5V to 5V does nothing. Connecting 5V to 0V will make shitloads of heat and melt everything if a breaker doesn't stop it. The increase in heat dissipation at the data line could be felt on both sides of the bus. In addition to arcing you have the possibility that the chip's lack of fortitude is causing data lines to flow more current, probably way more than normal since normal is almost immeasurably small. This could be within the ability of the game machine or maybe not. We know it wouldn't be anything the designers planed for since they were using 5V ROMs. These ROMs don't let the knocking on the door push the whole building down like the 3.3V ones do when you overpower them.

So is there a way to do this? Oh sure. Moving from one voltage range to another is just part of electronics design. It's not as simple as adjusting a level though. You need to give the bus a 5V door to knock on, and then pass that on as a 3.3V knock without any latency or hysteresis of any kind. It has to put out a perfect square wave just like the source but at a lower high voltage state.

The data line back from the cart to the bus will now need its 3.3V boosted to 5V. Again, it must be perfect and the extra voltage can't come from the 3.3V flash.

So presumably level modifiers are chips that do this. They can handle data coming in at one level of voltage and then pass it along at another without fucking up the data and while isolating each complaint so that everything works within its spec and can't have a low resistance component somewhere down the line causing high current draw.

Ok. So how many lines is that on a game cartridge? I think the guy say twenty some for a Genesis. Now look at that Neo cart.

Holy shit. Their PCBs will have to become much more complicated to accommodate this. Also, it's good to hear that the NeoSD thing is fully legit in this area. That certainly helps sell the case to me that that is a well make product.

As for a game Genie kinda thing...maybe, it depends on the system, but it would cost more than the POS flash cart you're trying to fix with it so you should just buy the next version of their POS, I guess.

I will fix those typos later...

Groover · 07/06/2017, 08:49 PM

I'm not going to pretend to say I fully understand the details. I do believe what Rene is saying and that the info is factually sound. I have a few flash carts. I'm game for a group buy of V2 TEDs. I have a version 1 and it has ben great but I don't want to harm my two duos and express. I also need to replace my Mega Everdrive. The 5X is supposed be compliant.

I understand some people saying that in real world use they have been ok. That is good to hear but why take the risk. It is like if I have a cigarette I don't just die from it but if I smoke over the years it will catch up with me.

I'm also dealing with my Genesis SCART cables possibly having boosted sync damaging my switch and Framemiester.