Can a japanese gremlins 2 be converted into mr gimmick?

I bought a cheap ebay famicom copy of gremlins 2 and it contains the sunsoft 5b chip. Would it be possible to convert this into japanese mr. gimmick with the audio wired up?

*edit*

Looking at the maskroms the prg maskrom of gremlins 2 has less pins haha d'oh. I also have a batman return of the joker, would it be easier desoldering the 5b and installing it in my return of the joker nes cart?

Yes.

I'm assuming you mean the Japanese release named Gimmick!, not the PAL release Mr. Gimmick.

You'll need to add the entire audio circuit, in addition to swapping the ROMs: Gremlins 2 doesn't have it (see Gimmick!)

If you do go through with this, we'd be grateful if you'd finish the pinout on the wiki.

Given that you're going to have to add the entire audio portion, it won't be "like new" looking... and if you don't have a desoldering station, I would recommend against trying to desolder the 5B. Airwires should be fine.

Yes japanese gimmick!

Here's what I figured out so far with the help of a friend based on gimmick! pcb pictures:

*deleted better schematic posted later*

The capacitor polarity is marked on the gimmick pcb picture but not the rating of the cap, since it's audio line stuff most audio caps are 10 uf from my experience.

Also need to figure out what part of the circuit pins 18 and 3 connect to.

Right now the big concern is the gimmick! pcb has a 32 pin prg maskrom where gremlins 2 only has a 28 pin prg maskrom. I'm terrible when it comes to wiring up nes / famicom carts for eproms.

I can desolder the 5b very safely I have the proper gear.

I previously RE'd the PCB to the same extent you have there, although I have a hunch as to what pins 3 and 18 connect to.

It seems likely that pins 3 and 18 is some kind of amplifier, it would be nice to test that. Hopefully those pins in In the Gremlins cart are floating; you should be able to use a 100k pullup/down or something on each of the pins and see if the other is driven the opposite way.

Fair enough. I'd like to encourage you to not destroy two cartridges to make one, but they're yours and I can't usefully say anything stronger.

What do you suppose the compatibility of this pirate cart is?
http://www.ebay.com/itm/Gremlins-2-Fami ... 3ccd7527c9

Haha probably not the greatest.


Believe me I'd much rather get this working in the gremlins cart I'm just not sure how much of a pain it is. Anyway I socketed the maskroms:









If I ever get this thing converted to gimmick I'll probably just hard solder in the eproms. These sockets are just for now. I need to order the right eproms to burn gimmick. Then I'll need to figure out the wiring....bleh...

グレムリン Gremlin in that logo looks dangerously close to グレムリソ Gremliso. In katakana, where does ン n become ソ so and ソ so become リ ri?

Anyway if someone could help me figure out the eprom wiring for this thing that would be much appreciated.

Direction of stroke may help you think about how these are distinguished.

so
n
ri

You can see that ン is dominated by left-to-right strokes, but ソ and リ are top-to-bottom. When written with brushes, the direction of stroke can usually be seen clearly (the Gremlins title screen tries to show a bit of stroke shape). It's harder to capture this in a small bitmapped font, but at least you should try to emphasize the horizontal orientation of ン to distinguish it from ソ.

The small stroke in リ should be vertical and slightly longer compared to the more diagonal stroke in ソ. Its long stroke is also more vertical than in ソ and does not usually extend as far left.

Context also helps disambiguate, as always, but sometimes ソ and ン are just going to mistaken for each other. There's probably an opportunity for a visual puns there too, but my grasp of the language is nowhere near strong enough to think of those.

http://wiki.nesdev.com/w/index.php/Mask_ROM_pinout

Yeah I'm a bit mentally handycapped with this. Sopposedly the eprom for the gimmick prg is going to be 32 pin and it's 256k, but the gremlins 2 pcb only has a 28 pin spot for prg which is 128k, would it be possible to wire that up?

Yes, it's doable.

Unfortunately, I'm not willing to give you a guide.

I don't mind as long as I know it's possible. I did a bit of research on it. My batman return of the joker pcb is wired up with the same pinout as 27c010 / 27c020 eproms. I desoldered the maskroms, dumped them, downloaded the rom of the game from the net, split the downloaded rom into chr and prj, and the crcs of the split files are identical to the maskroms I dumped. That's interesting this batman return of the joker fme7 pcb is wired for you to burn and drop in an eprom with no rewiring it seems.

The gremlins 2 famicom pcb is wired up for nes maskrom pinout so once I get some eproms I'll need to rewire it.

Sometimes even Japanese people screw up their own language, just look at filenames like "kikkomaso.swf" instead of Kikkoman.

Okay I looked at the gremlins 2 pcb. The chr maskrom is eprom compatible. I dumped the chr maskrom with my rom dumper without any rewiring, downloaded the gremlins 2 japanese rom, split the japanese rom, and the crc of the downloaded chr is identical to the crc of the dump I made using the maskrom. The gremlins 2 prg rom is nes wiring, not eprom compatible, so that'll require rewiring, and then there's the issue of wiring up a 32 pin eprom into a 28 pin socket.

*edit*

Okay I got the wiring figured out. Besides changing the wiring for the 32 pin eprom to work in the 28 pin spot I'll also need to connect a17 from the eprom to the prg a17 pin on the 5b chip. Hopefully this works.

Yes,but the ex-sound maybe not include in the gremlins's sunsoft 5b

Really? Oh well guess there's only one way to find out for sure.

That seems unlikely to me. Having another version of the 5b without the expansion sound would be pretty bad practise... why would you want indistinguishable chip variants around?

I'd say it's more likely that the 5a has the expansion sound than there is a 5b variant that doesn't. This is a question several people have posed, but nobody seems to have offered an authoritative answer on these forums yet. I wouldn't presume that it does, but it remains an open question. (My money's on no, but I think it's chances are better than there being a different 5b with no sound.)

I'm not sure

The question being "what exactly are the differences between the FME7, 5A, and 5B"?

I wish that byemu would post his findings in his native tongue, even though I won't be able to understand it.

That's exactly why I never really wanted to learn japanese. I mean learning two alphabets of 48 caracters is not too bad, but the fact some of them are alike is really confusing. There is also the mini-tsu characters which should not be pronounced "tsu", and so on.
Also even if you master perfectly kanas, you'll only be able to read text in old video games and kid's stuff because everything else is written with kanjis and you should study dozen of thousands of hours to learn all of them.

Like a lot of custom japanese chips there's a lot of questions without answers. The only real way to find out is to convert the cart to gimmick, wire up the audio circuit, plug it in, and see what happens. Also if anyone has better pictures of or can look at a japanese gimmick! cart pcb for me that would be very helpful. There's two capacitors at the top of the pcb, I want to know how many ufs and volts they are.

These caps:



The gimmick! cart audio circuit is completely reworked except for those caps values and which side of the 100k ohm resistor connects to which pin of the 5b (but there's only two possible spots so trial and error should do the trick). I'm pretty sure I have the eprom wiring all figured out. Now I'm just waiting on some eproms and resistors so I can build this thing (ordered them last night so this could take a while).

I'm more curious what the difference between the 5a and the fme7 is (the 5b is a bit obvious, it adds audio capability). I think the theory that the 5a is the earliest version is a good theory, which means the 5a could be identical to either the fme7 or the 5b. Without someone willing to convert a 5a cart to gimmick and wire up the audio pins we'll never know if the 5a has the audio capability or not.

Someone in the past made a Gimmick! repro using a 5A. There's no expansion audio.

Thanks a lot for letting me know! Well guess I'm going to find out if the gremlins 2 5b can do it.

Gotta love the japanese:



http://applesorce.b.sourceforge.jp/2011/09/27/%e3%82%b5%e3%83%b3%e3%82%bd%e3%83%95%e3%83%88%e3%81%ae%e6%8b%a1%e5%bc%b5%e9%9f%b3%e6%ba%90%e3%81%ae%e5%b0%81%e5%8d%b0%e3%82%92%e8%a7%a3%e3%81%84%e3%81%a6%e9%b3%b4%e3%82%89%e3%81%99%e6%96%b9%e6%b3%95/

Sunsoft 5b pin 2, never expected that. I guess pin 18 has been voted off the island. 1 uf caps, who'da thunk. I found this by going into google images and typing in "sunsoft 5b". I was hoping to find a better picture of the gimmick pcb, not the entire schematic. With the limited japanese I can read, I think this schematic says pin 2 is vcc. I guess pin 8 is the third sound output but gimmick only uses 2 sound outputs, and vcc helps...uhm...amp them?

It sure looks like he's using pin 2 there. And it definitely cannot be Vcc after the modification is done. And on the FME-7 pin 2 is PRG A18, not Vcc, which is a different kind of awful.
It is conceivable that pin 2 is the input to the amplifier, and it's tied to vcc to keep it from oscillating wildly. Given that he lifted the pins with some tape, that's conceivable.

The amplifier has got to be an inverter of some sort; the capacitors are clearly DC blockers.

... Oh, hey, he's got a very high resolution picture of the GRM-E301 PCB without ROMs in the way, I think I'm going to trace it.

Wait a minute...I need to lift my 5b pins?

Here's another random famicom cart that usually has a fme7 but possibly can come with a 5b:

http://rockn69.blog54.fc2.com/blog-entry-565.html

Honoo no Tokyuji Dodge Danpei

Have you a multimeter? Just test to see if pins 2 and 3 are connected to anything (especially ground and vcc) while it's off. If they're not, then you won't.
I'll get you a stronger answer after I've traced his photos.

Since we think pins 2 and 3 are an amplifier, you might be able to just skip that part of the schematic altogether and route the mixed audio back into the NES—but it might be too quiet. Or maybe you could use an external amplifier that's not part of the 5b.

Yeah I'll probe it later. Check it out...the batman sunsoft 5b cart:

Well, I can confirm that pins 1, 4-17, 19-23, and 33-44 are identical between the 5B and the FME7. 24-26 & 28 are very likely the same too.

I decided instead of lifting the pin just to desolder the entire 5b and cut the trace underneath where it sits. My experience with lifting pins is that they tend to break when being lifted so this seemed like the better option to me. I used a heat gun to safely desolder the 5b in record time. Here's how the pcb looks without the 5b there:



I disconnected pin 2 from vcc, the other pins needed for audio (3 and 27) are floating so those ones are all good. Here's the 5b resoldered with some pins soldered onto the audio pins so I can solder wires easily when the time comes:

I probed everything, all the connections are good and pin 2 is no longer connected to vcc. Gremlins 2 runs fine with pin 2 disconnected from vcc....thanks a lot sunsoft for making this 100x harder by needlessly connecting pin 2 to vcc underneath the chip.

*edit*

I wired up a fourth pin to the prg a17 spot of the 5b since that's been left floating. I'll probably need that pin wired up for the 256k prg eprom of gimmick!



It still runs gremlins 2 fine.

So first off, thanks a lot for that picture of the PCB with the SS5B removed; it lets me finish the trace with 100% confidence.
It's unfortunately necessary, amplifiers do bad things when their inputs aren't connected.
Actually it's ground. (it was connected to pin 6 also)
Yeah, that's just obnoxious.

Of course, now that pin 2 is known to not be PRG A18 on the 5B, I have to wonder if it's actually present on the 5A or FME-7...

Oh, I should ground pin 2 until I wire up the audio circuit otherwise something bad will happen?

Also since you appreciate depopulated pcb pics:

http://imgboot.com/images/Drakon/fme7desoldered.jpg

Batman return of the joker US cart with the maskroms and fme7 removed. The fme7 I didn't intend to remove but when I put the pcb down after removing the maskroms I placed it upside down and the fme7 fell out (I guess the entire pcb was still hot enough oops). I resoldered the fme7 back on and socketed the maskroms the cart works fine.

Eh, since you've already powered it up and it hasn't done anything, I wouldn't worry about it since you're not planning on leaving it that way. The canonical problems with leaving it disconnected are excessive power draw and causing interference.

oooooo.

But would you believe that no-one has a picture of the back side of NES-BTR? It's hard to figure out what pin 2 is connected to here without it

With possibility 10-15%. Discussion about Dodge Danpei was on FW while ago, but soon shifted to IRC.
Potencially ANY cart manufactured around Gimmick release date and based on FME7/5x can have 5B.

Oh okay, is there a manufacture date written on the case somewhere? Also is this exclusive to famicom carts or has anyone ever found an american sunsoft pcb with a 5b in it?


Well I re-attached pin 2 to ground for now it runs fine with it that way. I can believe what you say there's a lot of undocumented stuff out there. I'd really love to know what the av famicom audio circuit is. Also my hvc-cpu-gpm-02 famicom has almost the same audio circuit as the av famicom but with a slightly bigger low pass filter causing a little more muffle and a little more bass. Again I'd love to know the audio circuit of that famicom but the pcb is masked.

nes-btr solder side:

http://imgboot.com/images/Drakon/nesbtrsolderside.jpg

Pin 2 of the fme7 goes to a18 of the prg maskrom. Normally that would worry me but if you look at the solder side of the gimmick! famicom pcb:



a18 of the prg maskrom is connected to vcc, so all's good for using that pin of the 5b for the audio circuit when the cart is converted to gimmick!

Looking at the parts side of the gimmick! pcb:



a17 of the prg maskrom indeed is connected to pin 32 of the 5b. On my gremlins pcb pin 32 of the 5b is left floating, so I wired up this pin along with the audio pins:



This thing should now be ready to wire up when my eproms / audio circuit parts show up.

The thing that troubles me about this is that they've switched one pin, and only one pin, from an output to an input, and subsequently exchange which IC any given PCB is using seemingly willy-nilly.

Specifically, these two games (Gremlins 2 and Dodge Danpei) both use GRM-E301. Because of your rework, we know that pin 2 is tied to ground on that PCB. But Gremlins 2 (here) is using a 5B (where that's an input), and Dodge Danpei is using an FME-7 (where that's theoretically an output)

BBW-E301, DD2-E301, and PYK-E301 have solder pads to tie PRG A18 to either FME-7 pin 2 or Vcc, but they're all pre-jumpered for Vcc.
FC-DBT, NES-JSROM, NES-BTR, and NES-JLROM all tie FME-7 pin 2 to PRG A18.
FC-GMK ties PRG A18 to Vcc (obviously)

I mean, my problem is mostly that this is damage-causingly bad electrical engineering; either the pin is externally shorted and the game could destroy the output driver for that pin, or the pin is a floating input to an inverter. (Or ... whatever is true for the 5A)

There are a few kinds of input pins that can be either grounded or left floating without causing a problem.

An open collector output can be either Z (high impedance) or 0 (ground), never 1 (Vcc). /IRQ pins are often like this, where the pin is pulled up to Vcc through a resistor but any one of several devices on the bus can ground it. If one version of a chip uses it as an input but another uses it as an output, the other version's output can be made open collector to keep compatibility with old boards. The opposite is an open emitter, which is either Z or 1, relying on a pull-down elsewhere.

There are also input pins with a weak internal pull-up or pull-down. A well-known example of these in the NES is the CIC, where pin 4 (lock/key) has a pull-down that enables key behavior if pulled down. This is the origin of cutting pin 4 inside the console so that sync failure in a key-key system with no lock wouldn't cause resets.

There were capacitance problems with open collector outputs at high speeds. This led to widespread use of the three-state output, which can force 0, force 1, or get off the bus (Z), such as in National Semiconductor's Tri-state product line. ROMs, for example, are three-state devices: they output only when enabled.

Some pins may be bidirectional, where some data direction mechanism controls whether a particular pin is input or output. The non-RGB NES PPU has a data direction register controlling whether it reads the EXT pins for backdrop color or writes the current pixel's color index to the EXT pins. And of course, every RAM has a data direction input that controls whether D0-D7 is an input (/WE) or output (/OE). If one pin A is set to treat another pin B as always input, then B can be grounded without problem. An IC might even detect which board it's in by pulsing pull-up 0 and 1 voltages on the bidirectional pin. If it's grounded, perform one behavior; if it's tied to Vcc, perform another; otherwise, it's an output.

If only Visual 6502 weren't so backlogged.

No, there is NO MANUFACTURE DATE on the carts, but there is some unproven(yet) differences, related to date of manufacture.

pin2-pin3 is built-in amplifier or(which is most likely) CMOS invertor gate, used as amplifier. CMOS, so, if not used, input MUST be grounded.

Hint: look at release date(keep in mind, bootgod's database is good, but not 100% accurate) of Famicom carts and US releases.

Okay, so what happens if you don't ground pin 2 when it's not in use?

Oddly, I can't coax google into giving me any good visualization of it. So, here's what it won't do:
It won't catch on fire
It's exceptionally unlikely to cause permanent damage

The problem is "not connected to anything" isn't actually true; there's actually a little bit of capacitance between everything. And that little tiny bit of capacitance (roughly 1pF), when combined with the intrinsic inductance of the leads of the IC (about 3nH) can cause oscillations which drain huge amounts of power and cause massive interference. Sometimes either can be big enough to cause the game to stop working. Sometimes the oscillations can behave as an RF transmitter and cause problems in unconnected other devices.

I've experienced this before I wired up a circuit that divides a clock signal by 1/6, it worked but it was picking up stuff like an rf antenna and going in and out of working. I wired some floating pins to vcc and now it's completely fixed. Anyway as long as there won't be any damage that's good to know. These sunsoft 5b chips are really hard to find so the last thing I'd want to do is damage it somehow.