TD576
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Hello everyone!

I would like to get some advice, as I've seen the masterminds of GB hardware are hanging out around here. I'm not an engineer, but I understand the inteactions of certain systems.

https://hackaday.io/project/4291-homebr … -cartridge

So I found this project and I really like the simpleness of the whole cart. But are there any drawbacks?

Can I run Pokemon romhacks on this cart and save the progress? Could it be compatible with LSDJ?

I have in mind the creation of a bunch of dedicated carts for different stuff, thats why I'm not taking into mind any established flashcards yet.

I'm asking these because I'm confused if this one chip takes care of everything or not.

Thanks for all of your answers :)

Ben

catskull
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NUMBSKULL

That cart is rom only. That means no saving. It also means you can only use games that are 32kb or less, which is pretty much just maybe tetris.

TD576
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Yeah I was totally afraid of this, so back to the wire jungle I guess.

e.s.c.
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IL, US
catskull wrote:

That cart is rom only. That means no saving. It also means you can only use games that are 32kb or less, which is pretty much just maybe tetris.

or mGB/nanovoice/etc... regardless, not big enough for lsdj and without sav capability to really use it anyway

TD576
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Are there any guides/homemade cart superior to the one presented here?

http://www.reinerziegler.de/

e.s.c.
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IL, US

from what i know, there really aren't any diy solutions that will run LSDJ and be cheaper than the 64 Mbit EMS usb carts (at least after you factor your labor in)

catskull
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NUMBSKULL

Honestly with the BennVenn carts out these days it's almost pointless to even attempt a DIY solution, other than for learning but if you do that understand that you'll pour a ton of time and money into it.

Here's a link to one of his carts: http://store.kitsch-bent.com/product/be … -cartridge

He's also said a version that would cost half that may be in the works.

TD576
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Yes I've seen those cards. I'm not interested in buying them. And I'm pretty sure about home made cards being waaay cheaper than any GB flashcart product. Depends a whole lot on the purpose what you want to use them for. LSDJ is not that much important to me. I'm a bit more into homebrew games.

Jazzmarazz
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Michigan
TD576 wrote:

Yes I've seen those cards. I'm not interested in buying them. And I'm pretty sure about home made cards being waaay cheaper than any GB flashcart product. Depends a whole lot on the purpose what you want to use them for. LSDJ is not that much important to me. I'm a bit more into homebrew games.

Hand wiring smt ICs is only for the self-loathing. Trust me, I've done dozens.
Not only will you invest days and weeks into learning about rom/ram, memory mapping and bank switching but you'll need to buy rom chips, and an eprom programmer.

Rom chips with the capacity you need for a typical pokemon hack is going to be difficult to find and expensive becusse they are old and out of production. Newer chips with the capacity you'll want are going to be too small to wire pin for pin by hand.  It's not worth it, at least not for gameboy.

BennVenn
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Australia

If you're super keen to do this yourself, and i get it, I build things for the challenge too, not so much cost effectiveness - send me an email and I'll tell you all you need to know. Or drop by #GBDev on Efnet, lots of bright friendly guys willing to help you out.

In response to this: 'And I'm pretty sure about home made cards being waaay cheaper than any GB flashcart product' I disagree. As Jazz said, 5v flash IC's of the size and vintage you want are not in production, they will either be Old stock, recycled or they will use 3.3v products which presents a whole lot of issues in itself. Plus the MBC you'll need to re-purpose from another cart, or get stuck into CPLD/FPGA design.

You'll need to get PCB's made up, hot air re-flow station if you want to work reliably with SMD parts, Flash programmers, SMD ZIF sockets, Logic analysers (very helpfull!), JTAG interface + software for the CPLD/FPGA.

Not to scare you off, you can make one yourself but it will cost you a lot more than just buying an EMS/Smartboy/BV etc.... If you were to produce a batch of say 5000, then yes, it would be cheaper per piece - with a huge outlay.

TD576
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Welcome to the discussion guys. Okay so I'm not sure if you understand my mindset about the whole thing. I don't think this is gonna be as easy as pressing an "Add to cart" button. Actually I think this is gonna involve a whole lot learning which is awesome. Talking about costs. I was not referring to the coming soon cheaper cart. I don't think I could beat 12 dollars/cart regarding investment. But 25 is totally good to go. And it's gonna be fun belive me. I don't want to overcomplicate the whole process, altough the voltage difference is new stuff to me gotta research that. Also I can and will borrow equipment locally.

Also, I'm in planning phase, writing my shopping list. Assembly could only start at around January (of one lonely test card). I'm really happy if I can get some help from you guys if I get stuck somewhere. I would love to update on the progress.

[Also when buying equipment I'm not really calculating that into the price of my prototype, I will reuse them when expanding my library. Please think of this project as a way too complicated LEGO set. smile]

I can imagine how dumb this whole story must seem to you. But for me flashing the rom to the cart in 2 minutes would loose all of its beauty.

BennVenn
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Australia

Well all the best with your adventure! I do enjoy the design and debug phase of things and you sound like you're all set to go.

If you are interested, I have a few cart boards (homemade gameshark - Flash ROM + CPLD + voltage regs etc...) that would be a good dev board for someone that has the interest and motivation.

Oh, you might want to check out the price of a cart sized PCB with gold plating for the edge connector. You'll find your $25 won't go far. (Yes, gold plating is necessary, tin plating will cause more problems than it's worth and will screw with your gameboy's connector)

catskull
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NUMBSKULL

Curious about the gold plating. What's the issue with tin plating?

Also, random question I'll throw out here: do gb roms have headers like NES roms do? If you were to program a rom to a chip is it necessary to remove the header first?

BennVenn
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Australia

The header is integrated into the ROM, its there on the real cart as well as downloadable ROM's.

Tin oxidises rapidly, the oxide is an insulator which leaves you with intermittent contact. Tin is also soft and will alloy &/ transfer with the copper/gold  fingers inside the gameboy depositing the same oxide on the gameboy's contacts, which gives you poor contact with other carts you use thereafter.

jefftheworld
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Toronto, Ontario, Canada
BennVenn wrote:

Tin oxidises rapidly, the oxide is an insulator which leaves you with intermittent contact. Tin is also soft and will alloy &/ transfer with the copper/gold  fingers inside the gameboy depositing the same oxide on the gameboy's contacts, which gives you poor contact with other carts you use thereafter.

I can tell you from experience that you should never, ever use tin for this sort of application. The gold plating is not optional in any way.

TD576
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Yeah thanks for pointing out the oxidizing problem, new stuff for me too wink

Last edited by TD576 (Nov 15, 2015 4:40 pm)