Today, everyone uses ultra DMA mode. SCSI peripherals are connected in a daisy chain only through SCSI ports.
The cable goes to the host adapter, from which device 1, device 2, and so on. SCSI has a set of IDs. IDs range from 0 to 7, and between 0 and 16. Once all the devices have been installed, the terminals must be installed on the last device, which is to prevent echo signals from returning.
Bus mastering
Let’s talk about bus mastering later. Bus mastering is a technology used in controller buses today. In order to retrieve information from the hard disk, you need to request instructions from the CPU. Bus mastering was developed to address this vulnerability, as it now works directly from the bus mastering controller without requesting or requesting directions to the CPU, thus increasing the performance of a computer.