A bus mastering SCSI controller has it's own processor and it's own local memory.
Its hardware included three embedded SCSI controllers.
The ETRAX-4 had improved performance than previous models, along with a SCSI controller.
It is rumoured that overheating from the SCSI controller was one reason for the machine to never be released.
Try to find a SCSI controller these days.
The SCSI controller itself must use one of the IDs, typically the highest one, leaving room for 15 other devices on the bus.
Internal devices connect to a SCSI controller with a ribbon cable.
However, it is possible to add a SCSI controller as an expansion module.
This SCSI controller was mapped into the 68000's address space, and was considerably faster than the one on the Z80 coprocessor card.
Other features include two serial ports, Ethernet adapter, five drive bays and a SCSI controller.