ConsoleBus

The ConsoleBus provides system boards access to global system control and status as well as to the keyboard, mouse, and serial ports. In addition, there is a NVRAM/TOD chip that maintains the date and time and 8 Kbytes worth of data when the power to the system is shut off.

The state of physical hardware conditions is maintained in registers on the clock+ board. Each of these registers has inputs generated from other subsystems on the clock+ board, from other boards, or from the power supplies in the system. Some clock+ board registers are reserved for controlling various states of the machine.

The ConsoleBus also provides a serial port interface and a keyboard/mouse interface. The primary purpose of the serial port interface is to provide POST messages during power-on. The serial port can be used as a console for systems without a keyboard and display, and for standard serial peripheral hook-ups such as modems and printers.