Gameboy Development Forum
Discussion about software development for the old-school Gameboys, ranging from the "Gray brick" to Gameboy Color
(Launched in 2008)
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#1 2019-12-14 16:44:10
Is there an MBC1 clone out there?
In order for my game to contain everything I wanted in it, it turns out I will need to step up to a 64KB ROM file which means my 32KB flashcart will no longer do the job and I need to look into a larger cartridge.
I'm going to try to stick with a cartridge designed by me so that I have a bit more control over quality while keeping the cost down as I do plan to make a limited run of this game to sell at conventions. I wanted to see if anyone has designed an MBC1 clone chip, and what chips it would require, so that I can design a larger flashcart and possibly order a prototype run before the end of the year. I am not looking for a flashcart design that requires removing chips from existing Game Boy cartridges, I am trying to build a cartridge from all new parts.
I would also like to keep these as simple as possible as I am likely going to have to solder these myself and don't look forward to soldering 5+ surface mount resistors and capacitors along with 2 chips.
I've attempted to look into MBC1 clone searches, but everything I can find is MBC3/MBC5 or is talking about reusing an MBC1 from a cartridge instead of making new ones.
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#2 2019-12-14 18:33:24
Re: Is there an MBC1 clone out there?
What I have found so far was inside Gadgets had a series of posts about making an MBC1/5 hybrid using a EPM3032ATI44-10N CPLD, however that is discontinued and I'll likely have to pay more to get them now. It also runs at 3.3V, meaning I'll have to add an LDO if I go that route, pushing the cost up further. As far as I can tell, the specs I need to focus on for picking a new CPLD are:
-Maximum I/Os (32 on this one, but I'm pretty sure an MBC1 cartridge won't even use half of them as that is more pins than an MBC1 has in total.)
-Operating voltage (3.3 on this one, but I'm going to see if I can source a CPLD that uses 5V so I don't need to add extra parts to my schematic.)
-Maximum operating frequency (pretty sure it won't be an issue.)
-Maximum propagation delay (4.5s is what that chip has, guessing that's what I should aim for.)
I should note that I'm focusing my search on chips where I am able to find an ECAD model so I can use them in EAGLE more easily with a preference for fewer pins as I'll probably have to solder my prototype batch by hand since the PCB manufacturer I was looking at doesn't do assembly on thinner boards like what a cartridge would use.
Chips I'm looking at so far:
ATF750CL-15XU: Primary concerns are if it has enough I/Os and that the package might be too thick to fit under a shell.
ATF1502ASL-25AU44: Cheaper than the ATF750 and has more I/Os
I was looking at an SPLD, but I don't know if these are sufficient for MBC1 functions or not. ATF16V8CZ-15PU was the one I was looking at.
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#3 2019-12-14 19:38:27
- nitro2k01
- Administrator
- Registered: 2008-02-22
- Posts: 249
Re: Is there an MBC1 clone out there?
Why do you want specifically an MBC1 clone? MBC5 is superior in every way, even if you don't use all functionality it has to offer.
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#4 2019-12-15 07:34:17
Re: Is there an MBC1 clone out there?
I guess I don't have much of a need for MBC1 specifically, just preference because I guessed it would be easier to implement, would not require as powerful of a CPLD or put less drain on the Game Boy's battery.
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