Interesting detail:
"Inside the Nabu Personal Computer. The board on top is an optional floppy disk controller. Floppy disks were provided on the "developers version" of the machine, allowing it to boot CP/M and be used to develop Network applications.
The standard version of the machine also ran CP/M, however it was hidden from the user and no access was provided to the CP/M system prompt."
With this amazing info:
"Because of the lack of any applications software, some rudimentary math games were developed. Furthermore, the Heli-Tank game offered by the Japanese ASCII Corporation for its MSX home computer was disassembled and adopted to the reconstructed network. In fact, this game was originally published by NABU under the title Mania and, later, adapted for MSX."
Mabu PC seems to need access to a network via the "ADAPTOR" port to work. So it probably needs a hack and creation of a storage device to run a software. There is also a version for developers with a floppy disk drive. Maybe recovering the ROM from this one, network access would no longer be needed.