Figure 5-1 Clock+ Board - Sun Microsystems Enterprise 3500 System Reference Manual

FIGURE 5-1
5.2.1 OBP Version
For the Sun Enterprise 6500/5500/4500/3500 series, you must install OpenBoot
PROM code 3.2.24 or compatible versions when upgrading the clock+ board.
5.2.2 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 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.
Clock+ Board
TOD NVRAM
Extraction lever (in retract/insert position)
Captive screw (2)
Chapter 5 Clock+ Board 5-3