Cartridge dev tutorial?

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iGonzalez
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Cartridge dev tutorial?

Post by iGonzalez » Mon Aug 13, 2018 6:55 am

Hello all,
I'm an ex programmer who loves retro gaming, so of course in some moment I arrive here.

I have some questions, that I try to find the answer around (here and internet in general), but I couldn't find any thing clear. I feel bad asking it here, because I'm sure it is maybe a question answered 1 million of times. Actually I'm reading a lot about assembly and there is plenty of info about it, but I find more difficult to find something about the hardware part. So, my questions about it are:

-What is the best way to make a cartridge for develop? let's imagine I want to do a game for after it to make 100 copies (just for this example). What would be the best way to create the cartridge dev for testing? I saw something about using an old game removing the micros and changing them for some ones you can rewrite. Is this the best way? is there any good tutorial about it? I want to write the micro straight, I don't want any kind of emulator with a sd card or similar things.

-On the other hand, do you know, when people create a kickstarter with a nes game, where does the buy the pcbs? because there is plenty of cartridge shells on aliexpress or similar, but I couldn't find anything for pcbs. Of course this second question is more secondary, it was just for curious.

Thanks so much for any help, and I'm really sorry if there is a so repetitive question, but I couldn't find a clear answer about it :D

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Fisher
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Re: Cartridge dev tutorial?

Post by Fisher » Mon Aug 13, 2018 7:06 am

iGonzalez wrote:What is the best way to make a cartridge for develop?
I think that's a legit use for a repro game.
There's an example of how to do this here.
iGonzalez wrote:where does the buy the pcbs?
I think a good option woud be Infinite NES Lives.
Good luck and have fun. :wink:

iGonzalez
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Re: Cartridge dev tutorial?

Post by iGonzalez » Mon Aug 13, 2018 7:11 am

Fisher, thaaanks so much for the quick answer! I will take a look to the tutorial you said asap :D :D

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rainwarrior
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Re: Cartridge dev tutorial?

Post by rainwarrior » Mon Aug 13, 2018 11:16 am

iGonzalez wrote:I want to write the micro straight, I don't want any kind of emulator with a sd card or similar things.
PowerPak or Everdrive split the difference by loading the data off a SD card into hardware that very closely matches the original behaviour. (Depending on your point of view this may or may not be "emulation", but I think a lot of people consider FPGA hardware recreation a completely different tier than an "emulator".) There are some very minor differences between one of these and a cart built from scratch, but for development purposes they are extremely useful and versatile, and relatively inexpensive compared to other costs involved in developing NES software.

One thing you may or may not know already is that NES cartridge hardware comes in a lot of different flavours (i.e. "mappers"). If you make a dev cart, it will only support one specific mapper. Generally when someone is getting to know NES programming they will need to become familiar with several mappers to get an idea of what's going to fit their needs best. A PowerPak or Everdrive's FPGA solution makes testing different mappers a lot easier.
iGonzalez wrote:On the other hand, do you know, when people create a kickstarter with a nes game, where does the buy the pcbs? because there is plenty of cartridge shells on aliexpress or similar, but I couldn't find anything for pcbs. Of course this second question is more secondary, it was just for curious.
Myself I just let InfiniteNESLives make the carts. The do sell the PCBs and other parts too if you want them. Many people have designed their own boards and had them fabricated by a company that does that (there are lots of these, the cost efffective ones seem to usually be in China). Memblers made a board he calls GTROM or Cheapocabra that he's shared with a few others. Batsly Adams made his own board for Super Russian Roulette. RetroUSB / bunnyboy used to sell "repropak" boards that I liked a lot and used for a while, but I don't think they publicly offer that anymore. (I suspect would make a deal privately.) Game-Tech US sells a "ReproX" PCB. There's a lot of these around.

Actually the old ReproPak manual is kinda close to a tutorial situation, which might give you some idea of what parts go on a board like this:
https://www.retrousb.com/product_info.p ... ucts_id=42

The ReproX board has a similar guide:
https://www.game-tech.us/use-reprox/

InfiniteNESLives boards come with the components already on them and are re-flashable directly on the board, which is a lot more convenient than swapping socketed EPROMs:
http://www.infiniteneslives.com/nessupplies.php#pcb

If you wanna cannibalize an old game, the process is basically desoldering the 2 ROM chips and replacing them with sockets you can use for EPROMs. (May require some extra rewiring around the socket, Nintendo didn't use standard pinouts.)

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samophlange
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Re: Cartridge dev tutorial?

Post by samophlange » Mon Aug 13, 2018 12:25 pm

I might be wrong, but I think that InfiniteNESLives is making an updated flasher that works over USB for the NESMaker project, and they'll probably be selling those from their site once the kickstarter pre-orders have been fulfilled. Buying that and one of their pre-made carts sounds a lot easier than frankensteining old NES cartridges.

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Memblers
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Re: Cartridge dev tutorial?

Post by Memblers » Mon Aug 13, 2018 9:44 pm

I still need to set up an online store for GTROM or something. It has a couple advantages:
Currently $9.25 each for assembled/tested boards, pretty sure it's the cheapest option.
Connects your NES to USB port, you only need to power cycle the NES and run the upload program, instead of swapping carts or chips around. 512kB uploads are pretty darn slow, though the software could be improved and sped up. Seems like most people use emulators anyways, when it comes to testing.

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Sumez
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Re: Cartridge dev tutorial?

Post by Sumez » Mon Aug 13, 2018 11:43 pm

Yes, I have never found the need to test on a real NES as I'm developing. Usually the issues you will have playing on a real console is related to missing initilization stuff. Almost every other aspect seems to be emulated well by one emulator or another (Nintendulator and Mesen have been good to me).

iGonzalez
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Re: Cartridge dev tutorial?

Post by iGonzalez » Tue Aug 14, 2018 2:51 am

First things first, thanks to everybody, it is so nice to have a lot answer in no time, definitely I'm in the right place for start developing for the nes :D
Memblers wrote:I still need to set up an online store for GTROM or something
That sounds brilliant, and I will be following it. Honestly this step is quite early for me, my main "worry" was to know if in case I finish developing something interesting, if I could reproduce it in a cartridge easily, of if I would need to think about some kind of restrictions while I'm developing it (I mean thinking on do copies).
rainwarrior wrote:PowerPak or Everdrive
I was reading about this now, and I think I understood it wrong before. It looks like the easier way to try the game in the console so I will probably finish getting one of this ones...

So, for what I understand this one would be a good workflow for me in this moment:
1. Program and test the game in an emulator on the PC
2. If I want to test it on the console, test the game with powerpak or everdrive
3. If I want it in a cartridge for whatever reason I have, then I can get one board from for example Memblers, and have my game in my cartridge.
4. In the case I need X copies, I would just repeat the process 3 but in a bigger number.

The point is, this boards get "any" mapper for example? I mean, I develop the game "in any way" and then I will not have a problem for pass this game that is working ok on powerpak to a "proper pcb"?

Thanks a lot guys!

iGonzalez
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Re: Cartridge dev tutorial?

Post by iGonzalez » Tue Aug 14, 2018 3:02 am

Quick question about Everdrive. I saw there is different versions, one chinese, of "official Krikzz"... does it matter or it is the same but with different prices?

It looks easier to find the everdrive than the powerpak, I understand that basically it is the same thing but with different names, am I right?

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Re: Cartridge dev tutorial?

Post by tepples » Tue Aug 14, 2018 5:02 am

If you're buying an EverDrive N8, buy one from a authorized dealer. Counterfeits have been seen to stop working and not to work well with system software updates to support new mappers and the like.

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Re: Cartridge dev tutorial?

Post by iGonzalez » Tue Aug 14, 2018 6:30 am

Cool, thanks teeples

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Sumez
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Re: Cartridge dev tutorial?

Post by Sumez » Tue Aug 14, 2018 10:41 pm

Don't Everdrives have the famous 3.3v issue?

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rainwarrior
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Re: Cartridge dev tutorial?

Post by rainwarrior » Tue Aug 14, 2018 11:51 pm

Sumez wrote:Don't Everdrives have the famous 3.3v issue?
The NES one is fine, AFAIK:
https://db-electronics.ca/2017/07/05/th ... erdrive_N8

As for the other Everdrive carts for other systems...? I haven't really looked into those. (Krikzz did respond to the above criticism, FWIW.)

Personally I prefer the PowerPak for a number of reasons, but the Everdrive N8 seems pretty good to me (as long as you don't have a CopyNES mod, or want to play NSF music).

iGonzalez
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Re: Cartridge dev tutorial?

Post by iGonzalez » Wed Aug 15, 2018 1:48 am

That sounds cool. The only problem with the powerpak is that it doesn't look easy to buy it on UK. I will do a priper search before to buy the everdrive.
Thanks again!

Edit: Ok, I investigated it and I can get it send to UK from the US :D so I guess I will go for the power pak then!

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tokumaru
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Re: Cartridge dev tutorial?

Post by tokumaru » Wed Aug 15, 2018 12:54 pm

The main advantages of the N8, IMO, are the lower price and the fact that it takes SD cards, rather than CompactFlash, which are much harder to find these days.

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