Recent content by NathaanTFM

  1. NathaanTFM

    Hardware Project Open source flashcart project info

    yes, ROMs have an option to send a copy of their ROM which includes their header 1740076556 http://problemkaputt.de/gbatek-ds-cartridge-i-o-ports.htm This is not fully correct, but the important information is that the actual gap between command and data transfer is gap1+gap2, which is in...
  2. NathaanTFM

    Hardware Project Open source flashcart project info

    I don't know much about flashcards OS, but the only thing I can tell you is that the ROM timings are in the ROM header - it contains the delay between the command and the data. Also apparently Chip ID contains a bit that changes some behaviors with data transfers (repeated commands?) but I...
  3. NathaanTFM

    Hardware Project Open source flashcart project info

    Well, it's OCTO-SPI as it's just a CLK, CS and data pins. You have two encryption layers: - "KEY1" (name from nocash), the 8-byte command is encrypted and you have about 2300 clocks cycles to decrypt it (it's blowfish). Pretty easy to implement with a MCU as 2300 clock cycles @ 6.7MHz is a LOT...
  4. NathaanTFM

    Hardware Project Open source flashcart project info

    NDS is just a OCTO-SPI slave. You only need to make sure you can get those timings right (immediately send data when pin goes low) and get the data encrypted in time. Then it's just a matter of connecting things together. Hope you have fun in that project!
  5. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    I mean, the goal for my card was to run DS games. I was not planning on doing a flashcart. Might take a look at this some day, but DSPico is already doing just that and I'd start from scratch and rewrite these game patches myself anyway (if they're required, and I'm confident they are because a...
  6. NathaanTFM

    Hardware Misc Others Project 3D Printing DS cart shells?

    I have printed this model with various materials on JLCPCB. For what it's worth, the best material for it was "8228" (it was the most precise and fits a 3DS slot well). You can't print the cover though, so you'd have to make a new model.
  7. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    If you want to write your own program for your microcontroller, I think the best I can do is to explain how mine currently works? I'm not an expert in this field so there are most likely some parts that are wrong. The DS cartridge protocol is documented on GBATEK. It works like SPI but with 8...
  8. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    I'm working on a budget with chips I can afford, and there's also limited space on a physical cartridge, so the best I can use are SPI NAND FLASH chips, which have slower read speeds. I have looked at some more SPI NAND flash chips, and it turns out the "slower" transfer rate (240µs before...
  9. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    It still probably has to circumvent the DS security to reduce the read rate - I don't know a NAND chip able to load a 200h bytes region (at least, the first byte) in 5 us. But if you manage to increase the gap count before the game loads, then a NAND chip would definitely be fast enough without...
  10. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    It's definitely more of a novelty than an actual product (the initial goal was to find a way to distribute my homebrew game without buying a bunch of aliexpress R4s because those usually suck). Making a flashcard could be interesting, but it would require "on the fly" game patching (like the...
  11. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    Hey, I've finally got some good news! I'm working on a budget so I can't afford debugging tools and that's one of the reasons it takes so much time. But I've bought some cheap logic analyzer clones and it helped me debug the remaining issues! Turns out I was handling incorrectly some ARM state...
  12. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    I've put the original SM64 ROM on the flash memory and managed to boot to the Nintendo logo. Unfortunately, probably the lack of the backup EEPROM prevents the game from going further. It doesn't seem like my current setup allows me to "simulate" this chip with the microcontroller - I'll give...
  13. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    Can't currently give any update, but I'm definitely not giving this up and still planning to eventually open-source everything. Don't have enough free time for now, sorry!
  14. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    That choice was only due to the fact that this was my cheapest option (and only one) on JLCPCB that had a chance to be fast enough. I looked at many other STM32 uCs, but none of them were available and I don't think I can request a part to only produce 5 pcbs. For reference, for qty=5, the...
  15. NathaanTFM

    Gathering DS flashcard knowledge - DIY "opencard" idea

    Quick update on the cartridge: I have ordered a new prototype that is correctly wired to the SPI chip, and it seems to work (at least with DSi and 3DS - don't have a regular DS) I haven't implemented the SPI protocol yet (between the console and the cartridge), which prevents commercial games...
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