Open Source Cart Reader

[Note]

Just wanted to share some info on this device, the Open Source Cart Reader. It seems similar to a Retrode, in that it gives you the ability to back up saves from cartridges, back up game cartridges to ROM files, restore game saves to physical cartridges, back up and restore save games stored on N64 controller paks, and write game ROM files to game cartridges on compatible carts with EEPROMs.



The device is compatible with carts from the following systems:

- NES/Famicom
- SNES/SFC
- N64
- N64 controllers and controller paks
- SMS
- Genesis
- Game Boy
- Game Boy Color
- Game Boy Advance

I haven't pulled the trigger on the device yet, but I do have various games in which I'd really like to back up the save files onto an SD card or my computer. Years ago I was interested in a Retrode, but I wasn't able to grab one, so this might be a good alternative. Does anyone have any experience with this device? Would love to hear about it, if so.

[pierrot]

I bought parts for an OSCR years ago when it was at Ver 4, and didn't get around to building it until the middle of last year. I was able to get about 95% of my save files backed up off of carts with a healthy amount of persistence to get readable data, but it's not really what I would call an elegant solution.

I would hope that the latest revision fixes at least some of the various potential failure points for building the unit, but I haven't actually looked at it in any detail to know. Ver 4 has some pretty terribly hacky connectorizing of the battery board, though. It's been a while since I used the thing, but if memory serves, it only powers up off of a lithium battery cell in that battery board. It looks like Ver 5 actually fixed this by getting rid of the battery board. (I don't understand why it even would have been part of the design to begin with.)

Honestly, it's a little bit of a piece of shit, because it's designed around a Chinese Arduino clone with absolute dogshit quality control. I ended up needing to get two of the controllers because official Arduino products aren't mechanically compatible, and the first of the clone boards I got didn't have the bootloader. I tried to flash the bootloader with an authentic Arduino that I have, but it would just lose it on restart. The second one I got had a resistor on the USB port that was so poorly soldered it was basically just suspended horizontally in air, attached on only one side by a ~.2mm strand of solder, and I believe the diode was blown out on it (or just missing; I don't remember which). I was able to fix that just by resoldering the resistor and grabbing the diode off of the original defective clone board I got which was fortunate, because I was pretty close to having to go back to the clone roulette. The clones are really not a cost savings over authentic Arduinos for this reason, but the clone is the only option for the OSCR without hacking together a custom pin conversion solution.

I also recall having issues with the LCD screen, but I don't remember how it got resolved--.

I'm not necessarily saying don't go through with building one if you feel comfortable trying it, but just it's a pain in the ass and I have a number of issues with the design. Also there are a couple other things to keep in mind with it:

Ver 4 has modular cart connector boards, which is not necessarily all that great in practice, but it's basically the only option for Japanese Mega Drive carts (which for me is pretty much all I ultimately cared about for backing up saves). The N64 connector is too close to the Genesis connector to fit the JP carts on the all-in-one style OSCR. It's possible that there's just barely enough clearance if there's no N64 cart in that slot, but that's not an acceptable risk for me, personally.

For save files, the OSCR will dump raw save data. To do anything with it like playing on an emulator, or flash cart, you'll likely need this: https://savefileconverter.com/#/flash-carts EDIT: I don't remember a whole lot about what I was doing in great detail, but I was just remembering that I think I was only using the save file converter page for flash cart save formats. I only did some testing of N64 saves on emulator, because I didn't have an everdrive for N64 at the time, but for a number of those I had to swap the endienness in a hex editor for them to be readable by the emulator. It wasn't all of them, either. It was just sram saves, and a couple of the FLASH memory ones, or something like that.

[Note]

Appreciate your input on this, pierrot. That's too bad to hear that you had issues with it. It looks like now you can buy one pre-assembled, but the various other issues you described are concerning for sure, especially the save file format conversion issue.

I'm still interested in this, but I'm a bit hesitant. I guess I'll try to look up some more reviews about the latest model.

I realize I didn't include a link to the product's website in my original post, so if you want to check out the differences between the previous model and the latest one, you can here: https://www.cartreader.net/.

[pierrot]

Oh, I didn't realize there were people offering prebuilt units-- holy moly that's a lot of bread, though! Even taking out the hassle of building the V4 I don't think I could have brought myself to drop 250 bones on an OSCR. It's a kind of handy thing to have, but, damn.

There's a link to the github on that page, but just to point it out, it's an open source project and the parts and build instructions are in the wiki: https://github.com/sanni/cartreader/wiki/What-to-order
The estimated cost there of ordering the parts is around half the prebuilt price. I wouldn't really recommend doing this, anyway, because of the Atmega controller board, but it looks like it's even worse now because there are apparently newer vendors of the 2560 Pro with boards that only power on at 5V, and not 3.3V.
Anyway, all this is to say, there are some vendors at the top of the above github link that offer part kits for ~$125. That still feels like a hefty price, but I payed almost $100 for all the parts to then deal with the worse V4 rev, about maybe three years ago.

I was actually looking through the V5 pages for myself, to see if I want to upgrade my V4, and I'd have to rebuild the main board, but there's actually a PCB-only kit available on one of those distributors and all of the other components are the same as the V4 basically. I could just use the modular cart slots I built in place of the six slot adapter board. I might want to do that just so I can get rid of the battery board. I could also get the PIC adapter with it in order to dump my Mario RPG save file.

Anyway, V5 is a better option all around than V4, I would just make sure to let someone else take on the main risk of sourcing the 2560 Pro by getting a kit, at least. The prebuilt option should also be a safer bet for this, but man that price tag makes me squirm.

I was also looking through my backed up saves to try to piece together some of my memories about actually using this thing. I think newer everdrives actually might just read the raw save file data dumped by the OSCR. I have a lot of older models of everdrives that use file types that required converting with that previous conversion tool, though. There's still a lot of potential uses where converting the files could be necessary. It's also probably worth mentioning that the OSCR is supposed to dump ROMs to the no-intro specification, and the ROM file name and save file name need to be exactly the same to load them in everdrives or emulators. There might be some exceptions to that I'm not aware of, but that should be the case in general.