The OneBus from chipitos.be is based on the NUCLEO-F767ZI card from STMicroelectronics. The OneBus is equipped with IEC, IEEE488 and TCBM connectors as well as a cable network card and a WIFI card.
This cartridge (Paddle) allows you to add a TCBM bus to your C16, C116, PLUS/4. So you can connect the OneBus to the TCBM bus and enjoy faster speed. This cartridge is also compatible with the 1551 drive.