Both devices are emulated in openmsx I believe, so you should be able to get a feel for the functionality before committing to buy one (or both!)
ok, I didn't know it was possible to simulate the operation of the two cartridges in open msx, just download the simulator? Is it also possible in blueMSX that I have already installed on my pc? thank you
I don't really know about bluemsx, sorry. I'm using other platforms where it isn't available last I checked
Downloading openmsx is a start but for each cartridge you need some additional software (basically similar to firmware and configuration for the cartridge, I guess? I don't know the full details.)
For openmsx with Carnivore 2 this old thread may be a starting point: https://www.msx.org/forum/msx-talk/openmsx/question-about-ca...
For MFR start here https://www.msx.org/wiki/Emulating_MegaFlashROM_SCC%2B_SD_wi...
Also if you prefer Windows tools to MSX-DOS ones and get C2 you might read this thread about a management tool (I haven't tried it yet but the description and screenshots seemed promising): https://www.msx.org/forum/msx-talk/software/rom-collection-tool
In case you didn't see already, there were earlier discussions of these flash cartridges in comparison to each other, including https://www.msx.org/forum/msx-talk/hardware/mega-flash-rom-or-carnivore-2 and also https://msx.org/forum/msx-talk/hardware/mfr-vs-carnivore2-vs... (second thread is earlier and includes two other options also)
For Carnivore2 purchase you may contact these sellers:
https://sysadminmosaic.ru/en/msx/carnivore2/carnivore2#authorized_distributors
In addition to listing the authorized distributors, that same page has a serious contender for the best documentation with screenshots I have seen for any MSX cartridge. Amazing work, @Alexey and RBSC! I think short of trying it in an emulator or borrowing the real hardware from an understanding friend that page is the best way to get a feeling for this cartridge's feature set and also learn how to use it in detail
Also as mentioned on a linked page in addition to CF cards the C2 also works with many commonly available adapters for SD and microSD cards. I use this adapter these days and it never caused any problems: QUMOX microSD to CF Adapter with these microSD cards, formatted with both FAT16 and FAT12 partitions: SanDisk 32GB Extreme microSDHC UHS-I Memory Card
There is some leftover space due to Nextor limitations but it's still a huge amount of storage in MSX terms.
The very same microSD model also works great in MegaFlashROM SCC+ SD, which BTW is also well-documented both in the previous link's linked manuals (including for example the English one) and here: https://www.msx.org/wiki/MSX_Cartridge_Shop_MegaFlashROM_SCC... https://www.msx.org/wiki/MegaFlashROM_SCC%2B_SD_compatibilit...
In both cartridges the first usable partition from each memory card is mapped to a drive letter and you can use Nextor's MAPDRV (even from AUTOEXEC.BAT and REBOOT.BAT if you don't like to type it each time) to assign other ones to additional drive letters
Edit: thanks mods, I didn't know about amzn.com workaround for viglink URL problems!