System providing user definable selection of different data transmission modes of drivers of an I/O controller transmitting to peripherals with different data transmission rate

摘要

A computing system with a SCSI controller includes SCSI transmission mode selection apparatus and method to switch the transmission line drivers between transmitting in SCSI 1, SCSI 2 or another mode. The controller selects a maximum data transmission rate compatible with each peripheral device connected to the controller. A user-defined option code is decoded by the controller to provide the user with control over transmission mode options for the drivers in the controller. Based on the data transmission rate and the selected option, the controller selects the SCSI transmission mode to use for each driver type, acknowledge line or data lines.