Questions regarding the Yobo FC

[17daysolderthannes]

Well, to begin, I tried finding answers through search engines on the internet but 95% of people don't really know anything (just wild assumptions and speculation) and its too hard to sift through the crap and determine what is true and what isn't.

OK, so, I finally bought one of these and have had it about 2 weeks, and so far I like it, I just have a few questions that have until now gone unanswered:

#1 OK, apparently the "NES on a chip" everyone likes to name drop applies here. Obviously it must fairly accurately replicate the processes of a real NES in order to work at all, so what exactly is missing that keeps it from working with the 6~10 (depending on who you ask) incompatible titles? also, whats the deal with the Paperboy glitch where the game boots fine but the controller won't work?

#2 Could some of the incompatability be due to regional differences between the NES and the Famicom? I haven't been able to confirm whether or not the two are identical, so, for instance, does a US copy of Castlevania III work on an authentic Famicom with a 72->60 pin converter? I know this system is basically a Gametech Neo Fami with a 72 pin connector instead of a 60 pin, so it crossed my mind that it could be a reason.

#3 Has anyone ever tried putting an NES test cart (the one with the numbers/letters/colors that animate) in a Yobo to see if it passes? Does it pass? If it fails, where does it fail?

#4 Can someone link me to a picture of a "NOAC" without the gloppy cover? Also, what is the reason for the glop? quick assembly? corrosion resistance? electrical insulation? intellectual protection? all of the above?

#5 is it possible that the "inaccurate" sound and the chip/mapper missing that causes the few incompatible titles are due to copyrights rather than patents so to keep from infringing copyrights Yobo must deliberately alter the sound and leave out whatever chip/mapper that is necessary for the incompatible games? (long sentence, lol)

#6 Why won't Yobo FC controllers (USA version) plug into an NES while NES controllers work fine on a Yobo? Is it relatively easy to modify an FC controller to work? A major reason I bought the Yobo was so I could use its excellent turbo controllers on my NES. I think its because the NES pins are too thick for the Yobo controller, but just thought I'd ask.

That's all I can think of for now, please no "the Yobo sucks because its NOAC" posts without any actual answers (thats what I got on another NES board) and please no "search noob" flames either, I did search but I only got partial answers. Hopefully someone on here can help me out and give me some straight answers, I find most games play perfectly on the Yobo and for some reason I really like the idea of companies making new systems to keep retro gaming alive (unless you are an über purist, as I'm sure most of you are).

[Jeroen]

The only reason yobo is "crap" is the fact that it had to be cheap. It isn't that bad, but they didn't have the money to fully replicate (they didn't need to) It has nothing to do with famciom>nes.

[17daysolderthannes]

The only reason yobo is "crap" is the fact that it had to be cheap. It isn't that bad, but they didn't have the money to fully replicate (they didn't need to) It has nothing to do with famciom>nes.

well that covers #2, anyone else with answers for the rest?

[kyuusaku]

All NoaC are basically the same, it has nothing to do with the brand name. AFAIK the problem with incompatible titles is that the makers didn't know how to properly hook up the cartridge slot to the chip and broke compatibility with a few games that used the disconnected signals.

All the sound issues stem from the fact that they messed up inside the chip, and so all NoaC clones have the same sound issue.

Clones are very very accurate since they're cloned at a very low level, they will certainly pass all the tests.

There are other reasons to dislike clones than the few broken games and sound, I don't like clones just because they're always poorly fabricated and never convey the essence of the authentic console.

[17daysolderthannes]

I appreciate your responses, but you are still speculating. I am looking for 100% citeable proof one way or another, i.e. someone that disassembled one and took pictures and pointed out a flaw or missing chip etc. or someone that knows the specific workings of it down to the bare circuitry. Generalizations without references are no good to me.

I know what you mean about clones tending to be low quality. The Yobo FC (and I guess the Generation NEX, though its way too much for what it is) is actually not to bad. I was skeptical at first but I find the controllers are actually pretty solid and the system isn't terrible, it just seems cheap because its so incredibly light. At the very least it's as good as the TV plug n play games like Ms. PacMan or the Sega Legends collection. http://www.nesplayer.com/pirates/neofami.htm they took one apart and you can see the circuit board is actually pretty nice. It could be better, but its not bad at all.

[Jagasian]

#1: Every single flaw in the design of common Famiclones like the the NEX and Yobo is not known. That would be like asking of a detailed explanation of every flaw in the Windows operating system. A few problems have been figured out in detail, but nobody wants to spend the time debugging a crappy piece of electronics. They'd be better off spending their time studying the real hardware and designing a better clone. Also, you should realize that more than 6 to 10 NES and Famicom games have compatibility issues with the NOAC based clones.

#2: The problems are due to design flaws, some of which only show up with NES games and others with Famicom games. I have never tested the USA Castlevania III on a Famicom. As far as I know, it should work.

#3: The NES test cart doesn't test the kinds of things that are problems on clones. Even crappy emulators that run on a PC many years ago can pass the NES test cart's tests. The real tests are the NES and Famicom games.

#4: The glop for the NOAC is just an extremely cheap way to protect the circuitry of a "chip" that is mass produced. Without the glop on it, you'd still need a microscope to be able to see any detail.

#5: The NES system does not contain mappers, the cartridges contain them. The sound is inaccurate because of design flaws in the NOAC. This has been confirmed via black box testing of Famiclones. It has nothing to do with copyrights. If you want to know the details, search these forums for "noac", "nex", "famiclone", and "yobo".

#6: Not sure, but there was a similar issue with NEX controllers. Search these forums for the details, as it is probably the same issue.

[kyuusaku]

I am looking for 100% citeable proof one way or another, i.e. someone that disassembled one and took pictures and pointed out a flaw or missing chip etc. or someone that knows the specific workings of it down to the bare circuitry. Generalizations without references are no good to me.

Then do you own homework.

[bunnyboy]

#1 what exactly is missing that keeps it from working with the 6~10 (depending on who you ask) incompatible titles?

Those games are either MMC5 or four screen mirroring. The NOAC does not fetch graphics in the same way, so the MMC5 cannot track it correctly. There may also be voltage problems since some NOACs are now 3.3v instead of 5v. Many (most?) NOAC systems are wired wrong so four screen mirroring games don't work. NEX is a perfect example of this. No idea about Paperboy...

#4 Can someone link me to a picture of a "NOAC" without the gloppy cover?

Picture wouldn't be very interesting. The NOAC die is ~0.1" x 0.12" and would just look like shiny metal. There are ~80 tiny wires that go from the die to the pcb, all covered by the glob. I have a die around here somewhere but I may have sneezed it away.

#5 is it possible that the "inaccurate" sound...

If they were trying to avoid patent issues, they would have to change more than the sound. Someone figured out it is mainly just the duty cycles reversed, likely from not understanding or not caring.

#6 Why won't Yobo FC controllers (USA version) plug into an NES while NES controllers work fine on a Yobo?

Haven't heard this before, so I just checked it. The holes on the Yobo controller plug are too small for the diameter of the NES socket pins. You may be able to force it in there or cut away some of the plastic. Otherwise just cut the cord from a broken NES controller and solder it on there.

"the Yobo sucks because its NOAC"

Yobo/NEX/FC Twin sucks!

I find most games play perfectly on the Yobo

Must not have played too much of the original recently! Every color and almost every sound is different. I am certainly not a purist but the different sounds in games like SMB are super annoying. I also really notice the quality of plastics so I put the NEX a bit above the Yobo. At least all the people who don't notice the difference give me hope for future projects

[17daysolderthannes]

I am looking for 100% citeable proof one way or another, i.e. someone that disassembled one and took pictures and pointed out a flaw or missing chip etc. or someone that knows the specific workings of it down to the bare circuitry. Generalizations without references are no good to me.

Then do you own homework.

well, I was assuming someone already did it. This is NesDev afterall and supposedly the gurus of NES going ons, to me it seems like an afternoon's work to see the differences between a famiclone and an NES and what got lost in translation. Calling the sound differences and such a "design flaw" seems a bit too convenient and more like an excuse for not having a better answer. Sorry, but this is 22 year old technology, I seriously doubt a qualified electrical or computer engineer couldn't make an identical sound chip using today's technology. I may be sounding like a dick and get flamed for this but don't get mad at me because I asked questions no one apparently has the complete answer to.

[17daysolderthannes]

#1 what exactly is missing that keeps it from working with the 6~10 (depending on who you ask) incompatible titles?

Those games are either MMC5 or four screen mirroring. The NOAC does not fetch graphics in the same way, so the MMC5 cannot track it correctly. There may also be voltage problems since some NOACs are now 3.3v instead of 5v. Many (most?) NOAC systems are wired wrong so four screen mirroring games don't work. NEX is a perfect example of this. No idea about Paperboy...

#4 Can someone link me to a picture of a "NOAC" without the gloppy cover?

Picture wouldn't be very interesting. The NOAC die is ~0.1" x 0.12" and would just look like shiny metal. There are ~80 tiny wires that go from the die to the pcb, all covered by the glob. I have a die around here somewhere but I may have sneezed it away.

#5 is it possible that the "inaccurate" sound...

If they were trying to avoid patent issues, they would have to change more than the sound. Someone figured out it is mainly just the duty cycles reversed, likely from not understanding or not caring.

#6 Why won't Yobo FC controllers (USA version) plug into an NES while NES controllers work fine on a Yobo?

Haven't heard this before, so I just checked it. The holes on the Yobo controller plug are too small for the diameter of the NES socket pins. You may be able to force it in there or cut away some of the plastic. Otherwise just cut the cord from a broken NES controller and solder it on there.

"the Yobo sucks because its NOAC"

Yobo/NEX/FC Twin sucks!

I find most games play perfectly on the Yobo

Must not have played too much of the original recently! Every color and almost every sound is different. I am certainly not a purist but the different sounds in games like SMB are super annoying. I also really notice the quality of plastics so I put the NEX a bit above the Yobo. At least all the people who don't notice the difference give me hope for future projects

thank you for mostly answering my questions, except for the "famiclones suck" comment (joke perhaps?). Yeah, the quality of plastics of the NEX may be a little better but considering a yobo is $25 shipped and a NEX is a minimum of $60 I think the Yobo edges it out. Also, to say every color and every sound is different is being super anal about it. I played several games back to back and the differences were so small I forgot which system I was playing until I looked down to see which one was powered on. To me its like hearing a song on computer speakers vs. a car CD player, its the same music, just certain parts are emphasized differently, hardly enough to complain about in my book. I mean, really, if you play a DOS game on 2 different DOS computers they will play a little differently, so I find slight differences from NES to clone acceptable, though improvements are always welcome.

edit: oh yeah, I said copyrights, not patent. Patents have expired which is why these clones are legal now. I am pretty certain exact sounds would fall under copyrights rather than patents, though I am not certain since I originally thought NES sound was strictly midi but now it seems it is a low quality wave form, clarification would be welcome on this.

[tepples]

It's not copyright. There are four waveforms in the NES APU's pulse channels, and waveforms this simple cannot be copyrighted.

$4000/$4004: pulse waveform selection bits (NES)

$00: 1/8 duty cycle (10000000)
$40: 1/4 duty cycle (11000000)
$80: 1/2 duty cycle (11110000)
$C0: 3/4 duty cycle (00111111) (sounds exactly like 1/4 because the ear cannot hear inversion of a waveform)

Based purely on listening to sounds on an authentic NES vs. common NOAC based famiclones, it appears that the common NOACs appear to get the patterns for $40 and $80 reversed. I don't know what they do with the rarely used $C0 pattern.

[hap]

also, whats the deal with the Paperboy glitch where the game boots fine but the controller won't work?

Paperboy expects bit 6 to be set when reading the controller state, this is due to open-bus behaviour, effectively ORing the value with $40.

[Great Hierophant]

#2 Could some of the incompatability be due to regional differences between the NES and the Famicom? I haven't been able to confirm whether or not the two are identical, so, for instance, does a US copy of Castlevania III work on an authentic Famicom with a 72->60 pin converter? I know this system is basically a Gametech Neo Fami with a 72 pin connector instead of a 60 pin, so it crossed my mind that it could be a reason.

Castlevania III works just fine in a real Famicom if your converter connects all the active pins. Yobo and other NoaC-based pin converters do not and therefore that game will not work properly even on a real Famicom unless you use a true converter.

[17daysolderthannes]

#2 Could some of the incompatability be due to regional differences between the NES and the Famicom? I haven't been able to confirm whether or not the two are identical, so, for instance, does a US copy of Castlevania III work on an authentic Famicom with a 72->60 pin converter? I know this system is basically a Gametech Neo Fami with a 72 pin connector instead of a 60 pin, so it crossed my mind that it could be a reason.

Castlevania III works just fine in a real Famicom if your converter connects all the active pins. Yobo and other NoaC-based pin converters do not and therefore that game will not work properly even on a real Famicom unless you use a true converter.

So, in other words, could the compatability have a little bit to do with the fact it is originally a Famicom clone since it just a 60 pin connector expanded to 72 pin leading the extra pins to dead grounds (thats what I've heard)? Is the compatability with the Neo Fami (Japanese market version of Yobo FC) compatable with all Famicom games? I don't recall seeing any on the incompatable list when looking around...

[17daysolderthannes]

It's not copyright. There are four waveforms in the NES APU's pulse channels, and waveforms this simple cannot be copyrighted.

$4000/$4004: pulse waveform selection bits (NES)

$00: 1/8 duty cycle (10000000)
$40: 1/4 duty cycle (11000000)
$80: 1/2 duty cycle (11110000)
$C0: 3/4 duty cycle (00111111) (sounds exactly like 1/4 because the ear cannot hear inversion of a waveform)

Based purely on listening to sounds on an authentic NES vs. common NOAC based famiclones, it appears that the common NOACs appear to get the patterns for $40 and $80 reversed. I don't know what they do with the rarely used $C0 pattern.

So is the sound data purely stored on the cartridge the way an MP3 is stored on a hard drive, i.e. the player just plays back the waveform? I see what you are saying here (more or less) but the sounds don't seem swapped (i.e. plays drums when supposed to play bass) unless you are meaning the intensity is swapped (i.e. drums play louder than normal and bass is more subdued, because I find things like this do happen). I'm not saying your wrong, I'm just not fully understanding since I don't know 6052 or whatever the NES is actually programmed in.

To you and everyone else though, thanks for coming forward with this stuff, its good to hear stuff that isn't just blatant "it sucks cause its cheap" you hear all over the rest of the internet, you guys seem to know at least SOMETHING about how this stuff works and what the potential differences might be.