Reading real cartridges (Update - IT LIVES! - video)

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abrugsch
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Reading real cartridges (Update - IT LIVES! - video)

Post by abrugsch » Sun Jan 08, 2017 3:39 pm

So I've mentioned in on my build thread and in a couple of other places.... I have a prototype breadboard setup to read gameboy/GBC cartridges directly to the Pi. I've finally got my stuff together and routed out the first prototype PCB to have a standalone Pi cart reader HAT (well not a real HAT as it won't have the eeprom but whatevs.)
gbslurp-pcb.PNG
gbslurp-pcb.PNG (138.59 KiB) Viewed 3691 times
It's not done yet, I have to take a few measurements to make sure everything is spot on before sending to OSH (or wherever...) but apart from that, all the hard stuff is done.
Last edited by abrugsch on Tue Feb 21, 2017 6:01 pm, edited 2 times in total.

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Re: Reading real cartridges

Post by hesh.monster » Sun Jan 08, 2017 8:14 pm

Very cool indeed 8-)

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abrugsch
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Re: Reading real cartridges

Post by abrugsch » Mon Jan 09, 2017 10:01 am

Looking at this with my not half asleep head on I can reduce the size of this board by about half, with better component positioning, so I think I'm going to be re-working it totally tonight rather than shipping it off as is... it'll save me a load as OSH park charges by the square inch ;)

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Re: Reading real cartridges

Post by toiletpaper69 » Mon Jan 09, 2017 4:48 pm

Very cool. Good luck!

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abrugsch
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Re: Reading real cartridges

Post by abrugsch » Tue Jan 10, 2017 7:50 am

I'm nearly done re-routing this and with just rotating one of the chips 90 degrees, and moving the LED's around I've got the board down to the size of a PiZero with much neater routing so yay! need to re-do silkscreen labelling and then it's done!

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Re: Reading real cartridges

Post by Camble » Tue Jan 10, 2017 8:56 am

This looks interesting! What software do you need to read the cartridges?

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Re: Reading real cartridges

Post by abrugsch » Tue Jan 10, 2017 9:01 am

Camble wrote:This looks interesting! What software do you need to read the cartridges?
my own:
https://github.com/abrugsch/gbcartslurp

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Re: Reading real cartridges

Post by Camble » Tue Jan 10, 2017 9:08 am

Impressive :)

So you'll be dumping the ROM rather than reading the cart directly?

It also looks like you can write saves to a cart? Maybe even back up a save before replacing the battery?

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Re: Reading real cartridges

Post by abrugsch » Tue Jan 10, 2017 9:23 am

Camble wrote:Impressive :)

So you'll be dumping the ROM rather than reading the cart directly?

It also looks like you can write saves to a cart? Maybe even back up a save before replacing the battery?
yes, all of that. unfortunately in order to directly read the cart as a game cart, I'd also have to write (or at least integrate into an existing one) my own emulator since all the emulators rely on flat dumped ROM files (and the GB ROM is far from being a flat file unless it's an incredibly small one that fits into the first ROM bank. FYI, Tetris is one that does, but I haven't come across another that does...)
But the intent is to be able to boot a RPi and read an inserted cart if there is one and launch straight into the GB emulator, after dumping the cart and its savegame. then after playing and making saves (where aplicable) the savegame can be written back to the cart on exit.

Certainly savegames can be backed up before changing a battery and then be re-written to the cartridge after the battery swap - one of my goals for the project in fact

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Re: Reading real cartridges

Post by abrugsch » Tue Jan 10, 2017 9:36 am

I do have one major dilemma though...
I want to have this reader in my build, but I also want to have a TFT in DPI mode. Having DPI on the GPIO takes too many of the available pins and in fact takes I2C bus pins away. My other thought was to use SPI as the MCP23017 also has an SPI variant which is also faster (if I2C ends up being a bottleneck) but those pins are also obliterated even in RGB565 mode.
Grrr...

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