Gameboy Printer Emulation with an EMS Card?

Discussion of programming and development for the original Game Boy and Game Boy Color.
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RollRoundInTheToilet
Posts: 3
Joined: Mon Dec 16, 2013 7:04 pm

Gameboy Printer Emulation with an EMS Card?

Post by RollRoundInTheToilet »

I recently bought an EMS 64m SmartCard (Rolls right off the tongue, doesn't it?) and a Gameboy Camera, and I'm finding it hard to find a Mega Memory card online - at least one that fits into my low budget... But then I found a homebrew ROM on Google that emulates a Gameboy Printer. When I flashed it to the card and tried it out it seemed to save the images to the SRAM, but the sav image dumping program didn't seem to recognize it - evidently it only works with Gameboy Camera saves. I read in another thread somewhere that someone had used a Gameboy Camera ROM on a different flash card - but just as I feared it didn't work on the 64m.

Does anyone around here know if something like this can be done successfully?

Can the Gameboy Camera ROM be patched somehow to work on the card or can the ROM I found be used with a tool to extract the images?

Or am I going to have to track down a Madcatz link... and if so will a parallel to USB adapter work?
qwertymodo
Posts: 775
Joined: Mon Jul 02, 2012 7:46 am

Re: Gameboy Printer Emulation with an EMS Card?

Post by qwertymodo »

I don't have any experience with the EMS cards or the GBP emulator, but I can tell you that a USB-Parallel adapter will not work. They don't actually emulate the full parallel port functionality, only LPT printers. Personally, I'd keep hunting around for a MMC, they're really handy to have, for more than just what you're doing.
lidnariq
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Joined: Sun Apr 13, 2008 11:12 am

Re: Gameboy Printer Emulation with an EMS Card?

Post by lidnariq »

The objective is just to take pictures with the gameboy camera and use them on your computer, right?

It looks like Frohwein's emulator doesn't actually have any save memory, which explains why you can't get the images off it.

The documentation for the gameboy printer's protocol is complete enough that building a device that translated the printer's GB SPI protocol to serial or USB should be a nice project.
RollRoundInTheToilet
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Joined: Mon Dec 16, 2013 7:04 pm

Re: Gameboy Printer Emulation with an EMS Card?

Post by RollRoundInTheToilet »

Sorry for the long reply, but yeah, I guess I'll just wait until I can find a Mega Memory Card.
For now, taking pictures of the Gameboy screen works fine. Good thing my GBA SP Screen isn't very scratched!
Drenn
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Joined: Wed Jan 01, 2014 9:50 pm

Re: Gameboy Printer Emulation with an EMS Card?

Post by Drenn »

I'm thinking of making an SRAM dumping program, which would involve switching cartridges while the gameboy is on. It would copy the SRAM from the game to the system, then copy it back to the 64M flashcart. The Gameboy Color has just enough memory that it should work. Basically, this would eliminate the need for the memory card (though I have one).
nitro2k01
Posts: 252
Joined: Sat Aug 28, 2010 9:01 am

Re: Gameboy Printer Emulation with an EMS Card?

Post by nitro2k01 »

Drenn wrote:I'm thinking of making an SRAM dumping program, which would involve switching cartridges while the gameboy is on. It would copy the SRAM from the game to the system, then copy it back to the 64M flashcart. The Gameboy Color has just enough memory that it should work. Basically, this would eliminate the need for the memory card (though I have one).
You could also let the swapped Gameboy send the data over the link cable. (So the program would have two options, load into RAM and receive.)
Drenn
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Joined: Wed Jan 01, 2014 9:50 pm

Re: Gameboy Printer Emulation with an EMS Card?

Post by Drenn »

nitro2k01 wrote: You could also let the swapped Gameboy send the data over the link cable. (So the program would have two options, load into RAM and receive.)
It looks like the gameboy Camera has more sram than most ordinary games, more than can fit in Gameboy Color memory. So maybe the link cable idea is a good one. Either that or it can be dumped in 4 goes.

I got started on this, and aside from the above issue, it's actually working pretty nicely. I don't have my 64M yet, so I've been testing on bgb with its "load rom w/o reset" feature. But I think it would work on real hardware. I'll make a thread soon.

Edit: in its current form, this would let you dump the first several images in the gameboy camera.
RollRoundInTheToilet
Posts: 3
Joined: Mon Dec 16, 2013 7:04 pm

Re: Gameboy Printer Emulation with an EMS Card?

Post by RollRoundInTheToilet »

Drenn wrote: It looks like the gameboy Camera has more sram than most ordinary games, more than can fit in Gameboy Color memory. So maybe the link cable idea is a good one. Either that or it can be dumped in 4 goes.

I got started on this, and aside from the above issue, it's actually working pretty nicely. I don't have my 64M yet, so I've been testing on bgb with its "load rom w/o reset" feature. But I think it would work on real hardware. I'll make a thread soon.

Edit: in its current form, this would let you dump the first several images in the gameboy camera.
That sounds awesome... I'll keep an eye out for your thread!
nitro2k01
Posts: 252
Joined: Sat Aug 28, 2010 9:01 am

Re: Gameboy Printer Emulation with an EMS Card?

Post by nitro2k01 »

Drenn wrote:
nitro2k01 wrote: You could also let the swapped Gameboy send the data over the link cable. (So the program would have two options, load into RAM and receive.)
It looks like the gameboy Camera has more sram than most ordinary games, more than can fit in Gameboy Color memory. So maybe the link cable idea is a good one. Either that or it can be dumped in 4 goes.

I got started on this, and aside from the above issue, it's actually working pretty nicely. I don't have my 64M yet, so I've been testing on bgb with its "load rom w/o reset" feature. But I think it would work on real hardware. I'll make a thread soon.

Edit: in its current form, this would let you dump the first several images in the gameboy camera.
The problem is that there's a risk the Gameboy resets every time you insert or remove a cartridge. This is because of reset line glitching, and on DMG to a lesser degree bus possibly glitching since the work RAM is on the same bus as the cartridge. You can cut the reset line inside the Gameboy, or on the cartridge, but some cartridges rely on the reset line to be pulled high for their operation, so you may want to fix this somehow. I've solved this by using a broken Mega Memory in passthrough mode as an adapter, where I disconnect the reset lines, and pull the second cart slot's reset line high.

One of those projects that I want to do, but may never finish, is a universal cart swapping dumper/flasher. So this thing would copy itself to RAM, and then you would swap the cartridge, and then you can dump ROM or SRAM data in various ways. This could include link port, audio (which would be decoded by an application on the PC) or for smaller amounts of data, work RAM.
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