GBA early flash Cart questions.

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PhyChris
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GBA early flash Cart questions.

Post by PhyChris » Mon Aug 19, 2019 5:25 am

how were early on-board memory flash carts setup?
do the early flash carts work with the GameBoy Player? GBI?
are there any early flash cart schematics kicking around?
is there any ROM compatible RAM chips without the need of a memory controller?
do you see where I am going with this?
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Papy.G
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Re: GBA early flash Cart questions.

Post by Papy.G » Mon Aug 19, 2019 12:20 pm

Back in the days, you had "linkers" that were cart readers/writers that connected to Parallel or USB ports on PCs, there were also Magic Keys (NEO) that were early NDS homebrew devices, that can write on some of those early carts when put in the DS's Slot2.

They may work with the GBP, GBI booted or not, as long and as well as they work on the GBA.

They are mainly based on an ASIC emulating the MBC (Xilinx maybe), and any SRam/EEPROM/Flash chip that can handle the amount of memory and speed required. Getting the schematics won't help since the databus must be quite straightforward, while the other part won't lead you anywhere without knowing the inner programming of the specific ASIC.

I don't see where you're going with this, there are so many options (some great, and some not so good) to achieve the GBA Cart emulation around that it seems pointless to hassle making another one, especially if it has to be home made.
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Zelda WW with Tingle Tuner in split screen was what the GC RF modulator was made for! (Video)
PhyChris
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Re: GBA early flash Cart questions.

Post by PhyChris » Mon Aug 19, 2019 10:09 pm

OK, cool. I thought early GBA flash carts (1 game at a time) used some type of common multiplexed EEPROM without a memory controller or bank-switching.
I was thinking about A 'GBA RAM cart' that would use the GBP and homebrew to load and play ROMS from SD/DVD on the fly. There is already a homebrew GBP cart dumper, but i have no idea how the rom chips work. (not a lot of time to research lately)
I know it could be done with a GB/GBC cart and SRAM.

Thanks for the quick reply!
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Papy.G
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Re: GBA early flash Cart questions.

Post by Papy.G » Thu Aug 22, 2019 12:42 pm

I suppose both adress and data paths are limited so you have to have some kind of bank switching logic to adress huge amounts of data needed in games, plus the memory type selecting. Maybe very (I mean very) little programs that don't need specific features (extra RAM, game saving) can fit on a cart with little or no logic, as it was the case on the old GameBoy.
Most of the "second generation" of flash carts (those with a flash memory card support) are essentially that, they copy the game from the SD to the cart's RAM (seen by the GBA as ROM), then boots it.
By the way, someone recently asked if a Homebrew as GBI could be able to upload a game to a flash cart through the GBP before booting it from there, I eroneously answered that it can't be done, but Extrems wrote that it can. (I found it! It's there!)
DMG/MultiFreq OC/EDGB/EZF Jr, AGB/SC miniSD, NTR/NeoMK3, USG/flashme V8/SC miniSD
DOL001(EUR)/RGB/GCPlug/GBP/SD2SP2, RVL 001(EUR)/RGB/CMP/WiiSD

Zelda WW with Tingle Tuner in split screen was what the GC RF modulator was made for! (Video)
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