nesdev.org

So are you saying that, even though what I'm offering will support full MMC3 capabilities with 512KB PRG/CHR, the discussion alone of less support will confuse people and convince them not to go for it? I'm starting to consider that too, so that's why I started making statements about not concerning yourself with the minimzed version.

Until I figured out exactly how to separate the FULL mmc3 into 2 cplds it appeared that I might not be able to make it fit. For a little while I thought a minimized version might be the only option. That's not the case currently with what I've got compiled, it took a couple dozen compiles to find the winning fit. So that's kinda where the minimized thoughts started. Lets just hope there aren't any surprises when I finish assembling the proto and test everything out tomorrow hopefully.

Like you're saying, I think it's best to hold off on the minimized discussion because it even manages to confuse myself at times. The board will inherently support it because it only takes things away from the full MMC3. If your interested in more details a private discussion is probably best.

So I'm nearing the end on the PCB work. I was pretty happy with how much I was able to condense things to maximize the available area. I even snuck in a '377 8x FF w/enable and some '32 OR gates. So yeah the options are pretty open here, it's basically set up for everything except MMC2/4/5. So it can take the form of nearly all Nintendo boards. There are a fair number of solder bridge jumpers, but I kept them on the bottom side so it's cleaner and easier to keep an eye on everything. It also leaves space for a some good on board jumper legends to keep it simple, I also only pre-configured standard Nintendo mappers with the jumpers. If you want to create something obscure you're on you own.

The '377 8x flipflop and '32 is prewired up for all the inputs (D0-7, R/W, /CE). AO/MROM, BNROM, CNROM, and UxROM are configured with a few solder bridges on the outputs. If one wanted to play around with the other '377 outputs (D4-7) you'll have to jumper off the pin and wire things up however you'd like. But basically 95% of the work is done for you if you're looking to make a super UxROM or BNROM or something.

The perf board area ended up around 27x10 so sound chips and such should fit nicely along with some room to spare if the heart desires. I figure it'll also be good for such things as multicarts or other mapper and interfacing projects.

There's ~7 Free I/O on the top left CPLD (named "B") and a single I/O available on lower right CPLD "A". So those will be available for future use for extending capabilities or playing around with by advanced users. There should be a few free macrocells but not many for the FULL MMC3 for anyone curious.

So I'll finish the board this week and can now fully wire up my prototype fully test things before I put in the order.

MottZilla wrote:It's nice to see you're going to get this going. Be sure to post some pictures of a completely assembled pcb when you can.

Well here's a teaser of what it'll look like:




Here's what I've been starring at all weekend...

It also gives you a better idea of how I set up the DIP/SOIC setup on SRAMs.

I can guess why you've left the '377 as through-hole (ease of soldering for people who aren't practiced); I'm curious about why the '32 isn't SOP. (Not being distributed pre-soldered?) Are the discretes there so that you can just order one set of PCBs and populate as necessary? (Which would make sense...)

I'm also curious about what's preventing MMC2/4 support—pin count? routing complexity? a lot of work for only 4 games? If it is either of the first two it feels like a 5+ input AND gates should easily solve it.

Barely more legitimate (by NesCartDB profile counts, with 32 games vs 23 for mmc5 and 4 for mmc2+4): any idea how much of a Namco 163/175/340 you could fit? Obviously without sound or internal RAM.

Looks cool, can't wait to see a photo of a completed board. Good luck with testing.

lidnariq wrote:I can guess why you've left the '377 as through-hole (ease of soldering for people who aren't practiced); I'm curious about why the '32 isn't SOP. (Not being distributed pre-soldered?) Are the discretes there so that you can just order one set of PCBs and populate as necessary? (Which would make sense...)

Yeah I hadn't really considered making the '32 SMT. You're right about the '377 being TH for soldering ease. I did plan to allow the user to populate discrete mappers on their own, so I'll prob keep it DIP. That's not to say I won't consider supplying populated discrete boards. This way the user could buy some without having to make the decision in advance as to which discrete mapper they might use the board for.

There also isn't much room to be gained by going SMT on the '32. Although I did consider laying out some NAND gates for bus conflict avoidance. Going SMT with both those chips would allow them to fit in that space. The issue is I'd have to charge for populating and supplying parts. Assuming most users can't solder SMT the added cost and requirement to make up your mind at time of purchase is what deters me from going SMT on these. Plus I figure the perf area would allow for plenty of options if you want to toss in your own NAND gates for bus conflict avoidance and such.

I'm also curious about what's preventing MMC2/4 support—pin count? routing complexity? a lot of work for only 4 games? If it is either of the first two it feels like a 5+ input AND gates should easily solve it.

Really it's just the fact that I haven't recreated those mappers on my own yet. So I can't make the informed decisions about what signals need to go to which CPLD and such. Once this thing is running smoothly, I would like to consider other mappers. I wouldn't say I'm intentionally "preventing" them though. Actually I'm making them more possible by leaving the CPLD pins unassigned. I'll be adding some contact points for these unused pins. That way I could easily connect them wherever they are needed. Your probably right about pin count being an issue, and NAND gates being a solution. When the time comes I can simply add the NAND gates in the perf area and wire things up by hand. If demand became high for those configurations I'd consider adding the NAND gates to the layout as SMT. There is still a fair amount of free space near the power supply (top left).

Barely more legitimate (by NesCartDB profile counts, with 32 games vs 23 for mmc5 and 4 for mmc2+4): any idea how much of a Namco 163/175/340 you could fit? Obviously without sound or internal RAM.

The namco kinda fits into the discussion above as well. I'd also consider the FME-7/Sunsoft5, and RAMBO-1 to be possible but can't really say at this point. The real question with these is available logic. Out of all these I've only started redesigning the FME-7 and have it working partially, with IRQs not working yet. Off the top of my head It's pretty comparable to MMC3 in size. This will all be pending future development... If the need/market is really there I've got some sure fire solutions that would make use of a lattice CPLD/fpga. But quantities would have to be pretty high to make something like that cost effective, but that might not be the case a few years down the road with part cost/capability changes.


Related to the improvement discussion, but more acheivable with this board is the implementation of some sort of mapper hybrid MMC3. I'm trying to set it up as is to use the 32Kb VRAM as 4screen support. That would allow for 6-7 pattern tables, and 4 AT/NT to run as 4screen. I'd also like to play around with Tepples' idea of CHR A13 sensed scan line counter. Things like 32Kb WRAM as well. These would all be minimal logic to implement and provide significant benefits from the factory MMC3. Of course it's all moot if no one wants to develop a game using all this though. If I can ever put down the hardware long enought to create my own platformer, maybe I'll be that developer...

It's awesome to see this come to life! Would this project cover TN-ROM by any chance?

I can't say for sure but it's very likely TNROM will be supported.

SnoopKatt wrote:It's awesome to see this come to life! Would this project cover TN-ROM by any chance?

Thanks! And yes Mottzilla is correct, TNROM will be supported. That board alone was one not being available in the US is one of the biggest motivators for this project.

I've already recommended your board for that very purpose too. People wanting to make Final Fantasy 3. I hope this all works out and we see alot of new boards.

Ossum possum! You can definitely count me in for a board.

MottZilla wrote:I've already recommended your board for that very purpose too. People wanting to make Final Fantasy 3. I hope this all works out and we see alot of new boards.

and a lot less mario 2's sacrificed!

SnoopKatt wrote:Ossum possum! You can definitely count me in for a board.

MottZilla wrote:I've already recommended your board for that very purpose too. People wanting to make Final Fantasy 3. I hope this all works out and we see alot of new boards.

and a lot less mario 2's sacrificed!

Anyone that still thinks you need some rare 72 fingered version of Mario 2 to mimic TNROM style layouts is a fucking retard.
All you actually need is a basic TLROM pcb and half a brain to turn it into a TNROM with the ever so "uber rares 3774 FF3 engilshes".

nintendo2600 wrote:

SnoopKatt wrote:Ossum possum! You can definitely count me in for a board.

MottZilla wrote:I've already recommended your board for that very purpose too. People wanting to make Final Fantasy 3. I hope this all works out and we see alot of new boards.

and a lot less mario 2's sacrificed!

Anyone that still thinks you need some rare 72 fingered version of Mario 2 to mimic TNROM style layouts is a fucking retard.
All you actually need is a basic TLROM pcb and half a brain to turn it into a TNROM with the ever so "uber rares 3774 FF3 engilshes".

They are really not that rare, when I was first looking around for one, they were just as common as the non-72 pin version, and they were not any more expensive.
And of course you can do that, but it's quite a bit of work, and manually attaching a pin will never be as reliable as a real 72 pin cartridge from a factory. Unless there is some 72 TLROM cartridge, but after poking around on the database, I didn't see any. Even still, adding those extra chips would be tedious.

Once this PCB comes out, as far as TNROM is concerned (and probably the rest of the boards), it doesn't seem like the other solutions are worth the trouble, and not having to sacrifice again is alone a good reason.

nintendo2600 wrote:Anyone that still thinks you need some rare 72 fingered version of Mario 2 to mimic TNROM style layouts is a fucking retard.

Please leave your offensive comments elsewhere.

infiniteneslives wrote:

nintendo2600 wrote:Anyone that still thinks you need some rare 72 fingered version of Mario 2 to mimic TNROM style layouts is a fucking retard.

Please leave your offensive comments elsewhere.

While I think the comment is fine, it is a forum....but it'd help if he was at least right. Which he is not. TLROM boards to a MMC3 with 8KB CHR-RAM? find me one with the CHR-RAM R/W pin. I'd love that.

http://bootgod.dyndns.org:7777/search.p ... 9+20+41+53

There are none. Not even if you just pick out games that Konami made their own boards for with all the pins in their late years:

http://bootgod.dyndns.org:7777/search.p ... 9+20+41+53

I don't even know what else to say....way to go dude. You're proven you don't really know what you're talking about.

I believe he was talking about "adding" the pin. That's not a reliable method in the long term. But he was probably pointing out that the "rare fully pinned SMB2" cartridges are not the only way to make bootleg FF3 English carts.