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Vladimir, Russia

Hello everyone. Yesterday I’ve got a package from China with new Gameboy flash card called EZ Flash Junior. I didn’t found any info on web about it, so decided to share my experience with you. I downloaded LSDJ on it, and it work without any problems, save/load functions as well. I shot a short video for you to prove it works.

https://www.youtube.com/watch?v=3HIcAoor948

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NUMBSKULL

So basically this is the answer to the void left by the USB EMS carts. This is great!

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Toronto, Ontario, Canada

Since these use SD cards, I'm guessing the battery is fork the working ram in some way? Can you back up that working ram back to the SD card easily?

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NUMBSKULL

I think it is just normal 128k sram but it backs up on boot and then just loads it from SD when you choose the game. I think I saw there's a button in the cart that will make it back up immediately.

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Vladimir, Russia
jefftheworld wrote:

Since these use SD cards, I'm guessing the battery is fork the working ram in some way? Can you back up that working ram back to the SD card easily?

When you turn off your Gameboy, save is stored in battery powered RAM. When you turn Gameboy on, it asks to backup save to microSD, if not, it removes from RAM. Also you can choose auto backup on startup. The battery is also used for RTC.

Last edited by Feonaoh (Jan 26, 2020 9:50 am)

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Vladimir, Russia
catskull wrote:

I think it is just normal 128k sram but it backs up on boot and then just loads it from SD when you choose the game. I think I saw there's a button in the cart that will make it back up immediately.

The button on the cart is just a soft reset. But yeah, after that you can backup save to microSD.

Last edited by Feonaoh (Jan 26, 2020 9:53 am)

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Toronto, Ontario, Canada
Feonaoh wrote:

When you turn off your Gameboy, save is stored in battery powered RAM. When you turn Gameboy on, it asks to backup save to microSD, if not, it removes from RAM. Also you can choose auto backup on startup. The battery is also used for RTC.

That's neat, though. It's not quite as easy as having the data go straight to the SD card, but for a budget cart it's a hell of a lot better than having to rely entirely on battery-backed RAM.

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Vladimir, Russia
jefftheworld wrote:

That's neat, though. It's not quite as easy as having the data go straight to the SD card, but for a budget cart it's a hell of a lot better than having to rely entirely on battery-backed RAM.

I don’t think it’s technically possible to write save data straight to microSD for two reasons: flash memory is not random accessible and power off while writing can damage all the data on microSD. So the way it works seems very logical to me.

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Looks like it works similar to an Everdrive X-5 but at half the price.

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Toronto, Ontario, Canada
Feonaoh wrote:

I don’t think it’s technically possible to write save data straight to microSD for two reasons: flash memory is not random accessible and power off while writing can damage all the data on microSD. So the way it works seems very logical to me.

With the right microcontroller on the cartridge it wouldn't be unreasonable. You'd need to have reads and writes handled by the microcontroller. This device can already load save data from the SD card into a fast-access medium. I haven't seen the board, so I don't know if it's using a µc with on-chip ram or some sort of non-volatile ram/eeprom chip.

To get "real-time" saving to the SD card, a cartridge needs to handle read/swrites to the SRAM fast enough for the Game Boy but also perform buffered writes to the SD card. There are definitely microcontroller chips out there that could handle that but the additional development costs and even the per-chip cost would make for a more expensive product. At that point, you're better off designing something like the Drag'n'Derp, which is even simpler to use and more robust.

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Finally, a good replacement. I have been lurking around here hoping for this news smile