Super Game Boy Multicart in SNES Cartridge

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alanifamily
Posts: 4
Joined: Sat Nov 22, 2014 10:24 am

Super Game Boy Multicart in SNES Cartridge

Post by alanifamily »

Hey Guys,

I have an idea that I want to try to build but I am not sure if it is technically possible. I would appreciate your help and patience. I have seen the projects with EPROM but I do not want to do it that way (yet!).

My idea is that I want to put Pokemon Silver and Pokemon Gold and a Super Game Boy into a SNES cartridge (similar to this project http://imgur.com/a/dOHF8). I do not think there is enough space for all of it to fit into an SNES cartridge but that is not my main concern.

This is the equipment I plan on using:
Pokemon Gold and Silver cartridges
Super Game Boy
Wires
Working SNES
Quad 2-input Muliplexers

The way I wanted to go about this project is the following:
-A manual switch will be used to select which game will be loaded (for example, on would be pokemon gold and off would be pokemon silver)
-There are 32 pins from each gameboy game that will need to be connected to the super game boy
-(I am not sure if this step is feasible so please let me know if there is another way to do it) In order to switch the connections to the super game boy, I want to use a series of multiplexers in conjunction with the switch to switch the connections. The power will be coming from the super game boy.

My main concern is the method in which the connections will switch from one game to another.

I look forward to your replies!
Markfrizb
Posts: 607
Joined: Sun Dec 02, 2012 8:17 am
Location: East Texas

Re: Super Game Boy Multicart in SNES Cartridge

Post by Markfrizb »

Your best bet would be to get a double size flash rom and just do a bank switch. Have both programs in the rom and if it saves, you'll want to double the SRAM and bank switch that too. Only 2 wires to deal with for a physical switch. I'm not familiar with the sGB carts and how they function so I may be completely wrong.
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MottZilla
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Re: Super Game Boy Multicart in SNES Cartridge

Post by MottZilla »

If you wanted to do something as pointless as this, Mark's suggestion is the better way to go. But don't these Pokemon cartridges go for somewhat high prices? Why would you destroy one to make something this silly? As well as destroying a Super Gameboy.
alanifamily
Posts: 4
Joined: Sat Nov 22, 2014 10:24 am

Re: Super Game Boy Multicart in SNES Cartridge

Post by alanifamily »

MottZilla wrote:If you wanted to do something as pointless as this, Mark's suggestion is the better way to go. But don't these Pokemon cartridges go for somewhat high prices? Why would you destroy one to make something this silly? As well as destroying a Super Gameboy.
I wanted to learn how to do play around with electronics while making something different.

Doesn't Mark's method involve EPROM? I don't have the equipment to do that or the know-how. I was hoping this would be simple project with just a switch, some wires and soldering, and a few components.

Would the method that I suggested work? If it wouldn't, why not?
Markfrizb
Posts: 607
Joined: Sun Dec 02, 2012 8:17 am
Location: East Texas

Re: Super Game Boy Multicart in SNES Cartridge

Post by Markfrizb »

I had someone ask me to do a similar project.... I agree with Mott, what's the problem with using the cart the way it was intended (and that's was my response at the time)?

You probably could use switches and control the Rd/WR/OE/CE/ etc...at the cart edge. And buss both carts together assuming there's even room inside the cart for a second GB cart. Maybe you should learn how the EPROMs work and why. Flash roms that small should be available (yeah, you'd have to learn some smt work). If nothing else, you could just stack a second flash rom on top of the original one and just control (switch) the OE's with both lines having pull up resistors. Again, those games save your progress, you'd have to do the same with the SRAM (assuming you'd want to retain your progress of either game).....but battery life would be shorter with 2 SRAMs attached....

Group: Are the flash roms on GB's standard Flash roms? I don't know since I've never messed with the GB's carts
Markfrizb
Posts: 607
Joined: Sun Dec 02, 2012 8:17 am
Location: East Texas

Re: Super Game Boy Multicart in SNES Cartridge

Post by Markfrizb »

alanifamily wrote:
Would the method that I suggested work? If it wouldn't, why not?

If could work.... But it wouldn't be as simple as you are presuming.

So you want to jam 2 carts and several MUX chips inside a standard Snes shell..... That's a lot tougher than just swapping the EPROM and a few wires.
alanifamily
Posts: 4
Joined: Sat Nov 22, 2014 10:24 am

Re: Super Game Boy Multicart in SNES Cartridge

Post by alanifamily »

Markfrizb wrote:I had someone ask me to do a similar project.... I agree with Mott, what's the problem with using the cart the way it was intended (and that's was my response at the time)?

You probably could use switches and control the Rd/WR/OE/CE/ etc...at the cart edge. And buss both carts together assuming there's even room inside the cart for a second GB cart. Maybe you should learn how the EPROMs work and why. Flash roms that small should be available (yeah, you'd have to learn some smt work). If nothing else, you could just stack a second flash rom on top of the original one and just control (switch) the OE's with both lines having pull up resistors. Again, those games save your progress, you'd have to do the same with the SRAM (assuming you'd want to retain your progress of either game).....but battery life would be shorter with 2 SRAMs attached....

Group: Are the flash roms on GB's standard Flash roms? I don't know since I've never messed with the GB's carts
For the reason, I just want to make something interesting.

I will let you guys know how it goes in one or two weeks and will let you know how I got it done.

I didn't know about EPROM's before a few days ago and what you guys do on this forum is really exciting. Once I have the time, I will do it the EPROM way.
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MottZilla
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Re: Super Game Boy Multicart in SNES Cartridge

Post by MottZilla »

The problem with using two actual cartridges is there are multiple signals you need to then switch between which cartridge receives them. If you didn't care too much, maybe by switching which cartridge has the main enable signal connected might work. but it's still going to look absolutely awful. I don't think you'd have enough room to fit two gameboy PCBs inside the shell.

I imagine if you attempt this, at the end you will be left with either a mess or a mess and useless parts that may have been damaged.

I'm not intending to be rude but this is not a great project to start out with.
proveaux
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Joined: Wed Feb 15, 2012 10:19 pm

Re: Super Game Boy Multicart in SNES Cartridge

Post by proveaux »

Image
I made one, and It is very tight to fit one inside. Curious to see how you make it all fit and how you wire it to switch between games. You will have a Super Gameboy and 2 games that no longer work as intended, but if it works, it will look cool!
:)
alanifamily
Posts: 4
Joined: Sat Nov 22, 2014 10:24 am

Re: Super Game Boy Multicart in SNES Cartridge

Post by alanifamily »

MottZilla wrote:The problem with using two actual cartridges is there are multiple signals you need to then switch between which cartridge receives them. If you didn't care too much, maybe by switching which cartridge has the main enable signal connected might work. but it's still going to look absolutely awful. I don't think you'd have enough room to fit two gameboy PCBs inside the shell.

I imagine if you attempt this, at the end you will be left with either a mess or a mess and useless parts that may have been damaged.

I'm not intending to be rude but this is not a great project to start out with.

I understand. I will still go ahead with the project and let you know how it goes.
Markfrizb
Posts: 607
Joined: Sun Dec 02, 2012 8:17 am
Location: East Texas

Re: Super Game Boy Multicart in SNES Cartridge

Post by Markfrizb »

Feel free to post your questions as you go. This group (of great guys!) helped me with several of my projects questions and I'm happy to return the help to others. Out of curiosity, what is the flash rom size? Can you post that info? What chips are you going to use?

Maybe you should post what your general game plan is to accomplish your goals. Whether it fits or not or if we think it's crazy or not doesn't matter. This is the path you chose to learn and gaining knowledge is priceless.

I knew NOTHING about snes carts, EPROMs, buffers, MUX's, even pull up/down resistors. I had a very basic understanding of passive parts and electricity but I asked a lot of questions..... Did A LOT of reading and fact finding on the web, banged my head against the wall many times ( it helped! Lol) and I was able to learn AND accomplish my goals.

So good luck and hopefully we can help out.
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MottZilla
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Re: Super Game Boy Multicart in SNES Cartridge

Post by MottZilla »

alanifamily wrote: I understand. I will still go ahead with the project and let you know how it goes.
Be sure to ask questions if you have them and to plan ahead. As we've all said, it can probably be done. But doing it well needs careful planning.

One thing I didn't note, aren't Pokemon Gold and Silver better played on Gameboy Color systems? I thought they were GBC/GB dual compatible but no longer SGB enhanced like Blue and Red.
Sik
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Re: Super Game Boy Multicart in SNES Cartridge

Post by Sik »

Apparently Gold and Silver still support the SGB, Crystal doesn't though (although there are some leftovers from Gold in it).

Also Korean versions need a GBC (they need the extra video memory in order to fit hangul), but I doubt this will bother with that version =P
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