MSX2 with internal 512kb of RAM, what then?

If you only care about games, you can now load and run cracked megaroms for memory mapper (or many Megaroms via SofaROM), and most European disk based scene games that didn't work yet.

@manuel Mostly games yes, any recommendations for a simple eprom or eeprom based cart able to store cracked megaroms? Reading about SofaROM would require a MegaFlashRom SSC+ SD or Carnivore 2.

@sdnatcher73 Indeed I noticed that some games on disk that require additional ram play fine (parodius, penguin adventure) and some other don't. Will look for other sources.

Thanks for the info!

Well, it's just as Manuel says. But if you want to take the additional cartridge route, take a look at the SD mapper. You can buy it at various places, like the 8bits4ever SD-512. And you can find the schematics at Fabio Belavenuto's Github page.

Actually that cartridge has one drawback that will turn in your advantage. It can either be a 512K memory mapper or a 512K megaram cartridge. But not both at the same time. To boot Nextor, you will need a memory mapper. Usually this blocks the megaram option. However, you have the memory mapper available internally now, so you can use the device in megarom mode and still boot Nextor.

P.S. Alternatively, you can consider RBSC's Unimapper cartridge. Alexey posted an update just a few hours ago.

You can't load MSXDOS2 with loadROM or anything else. Don't waste your time on that.
SofaROM is probably a lot better than loadROM. Why not try that?

This is a great way to play ROM files. And when it's an SCC supporting game, the cartridge has one.
There are several cheap options for a donor SCC cartridge. F1 Spirit is often quite easily found for a few bucks. Especially when it's cartridge only.