The SC-3000 was the computer equivalent of the SG-1000, which itself was Sega’s first entry into the console business.
Users were able to create their own programs and games on the machine in BASIC, as well as machine code. Since games were compatible with both the SC-3000 and SG-1000, and since the SC-3000 was also able to run computer applications, it outsold the SG-1000.
Now, using custom hacked BASIC software this multi cart is able to load tape software directly into memory. The whole thing is versatile, comes with a bunch of homebrew and tapes games, and of course you can upgrade it to add your own SG-1000 ROM images. The Mk II Multi cart can play all the known SC-3000 or SG-1000 ROMs, and it currently supports 21 tape games.
Check it out here. Pre Orders are being accepted for a one off production run and are priced at $90 USD plus shipping / postage. I can see this being one of those things that becomes surprisingly pricey if the author only does one run.