EDIT 02-10-2022: This DESIGN is OLD and not available anymore...the new AIO-Multicart with case is available here.
Designing multicarts for rare/obscure game consoles is my current main interest.
I got interested in the Bandai Datach system and it's one of those systems which have no solution for Flashcarts so far...until now.
The cartridges fit perfectly inside the Bandai Datach and the PCB's should even fit inside the original cartridge-cases.
Here are the DIP-Settings for both cartridges:
At https://retrostuff.org/category/bandai/datach/ you can even find many of the needed Barcode-Cards, just print it and you can use it with your Datach-Barcode-Reader.